This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Example Input: Passage: From the caliphate's north-western African bases, a series of raids on coastal areas of the Visigothic Kingdom paved the way to the permanent occupation of most of Iberia by the Umayyads (starting in 711), and on into south-eastern Gaul (last stronghold at Narbonne in 759). Hisham's reign witnessed the end of expansion in the west, following the defeat of the Arab army by the Franks at the Battle of Tours in 732. In 739 a major Berber Revolt broke out in North Africa, which was subdued only with difficulty, but it was followed by the collapse of Umayyad authority in al-Andalus. In India the Arab armies were defeated by the south Indian Chalukya dynasty and by the north Indian Pratiharas Dynasty in the 8th century and the Arabs were driven out of India. In the Caucasus, the confrontation with the Khazars peaked under Hisham: the Arabs established Derbent as a major military base and launched several invasions of the northern Caucasus, but failed to subdue the nomadic Khazars. The conflict was arduous and bloody, and the Arab army even suffered a major defeat at the Battle of Marj Ardabil in 730. Marwan ibn Muhammad, the future Marwan II, finally ended the war in 737 with a massive invasion that is reported to have reached as far as the Volga, but the Khazars remained unsubdued. Question: Who defeated the Arabs at the Battle of Tours?
Example Output: Franks

Example Input: Passage: There is disagreement about the origin of the term, but general consensus that "cardinalis" from the word cardo (meaning 'pivot' or 'hinge') was first used in late antiquity to designate a bishop or priest who was incorporated into a church for which he had not originally been ordained. In Rome the first persons to be called cardinals were the deacons of the seven regions of the city at the beginning of the 6th century, when the word began to mean “principal,” “eminent,” or "superior." The name was also given to the senior priest in each of the "title" churches (the parish churches) of Rome and to the bishops of the seven sees surrounding the city. By the 8th century the Roman cardinals constituted a privileged class among the Roman clergy. They took part in the administration of the church of Rome and in the papal liturgy. By decree of a synod of 769, only a cardinal was eligible to become pope. In 1059, during the pontificate of Nicholas II, cardinals were given the right to elect the pope under the Papal Bull In nomine Domini. For a time this power was assigned exclusively to the cardinal bishops, but the Third Lateran Council in 1179 gave back the right to the whole body of cardinals. Cardinals were granted the privilege of wearing the red hat by Pope Innocent IV in 1244. Question: What year did the ruling "only a cardinal was eligible to become pope" come in effect?
Example Output: 769

Example Input: Passage: A true predator can commonly be known as one that kills and eats another living thing. Whereas other types of predator all harm their prey in some way, this form kills them. Predators may hunt actively for prey in pursuit predation, or sit and wait for prey to approach within striking distance, as in ambush predators. Some predators kill large prey and dismember or chew it prior to eating it, such as a jaguar or a human; others may eat their (usually much smaller) prey whole, as does a bottlenose dolphin swallowing a fish, or a snake, duck or stork swallowing a frog. Some animals that kill both large and small prey for their size (domestic cats and dogs are prime examples) may do either depending upon the circumstances; either would devour a large insect whole but dismember a rabbit. Some predation entails venom that subdues a prey creature before the predator ingests the prey by killing, which the box jellyfish does, or disabling it, found in the behavior of the cone shell. In some cases, the venom, as in rattlesnakes and some spiders, contributes to the digestion of the prey item even before the predator begins eating. In other cases, the prey organism may die in the mouth or digestive system of the predator. Baleen whales, for example, eat millions of microscopic plankton at once, the prey being broken down well after entering the whale. Seed predation and egg predation are other forms of true predation, as seeds and eggs represent potential organisms. Predators of this classification need not eat prey entirely. For example, some predators cannot digest bones, while others can. Some may eat only part of an organism, as in grazing (see below), but still consistently cause its direct death. Question: What do box jellyfish use to hunt their pray?
Example Output:
venom

