Instructions: In this task, you're given a question, along with a context passage. The passage will not have a direct answer to the question, but can include some information and a clue for the answer. Assuming you can only obtain information about one entity in the passage, your job is to determine whether information from the passage can be used to answer the question. Indicate your choice as `a` for Yes or `b` for No.
Input: Question: How old was Khan in 1259? Passage:Despite the weakness of the Song military, they managed to slow the Mongol Empire advance for decades. The Song resistance led to the death of Möngke Khan, in 1259, at Diaoyu Fortress. The resulting withdrawal of the Mongol forces, for the customary kurultai to select a new Khan, ultimately led to the Toluid Civil War which divided the Mongol Empire. Möngke's brother, Kublai Khan, who already controlled Mongolia and China's northern territories, formerly part of the Jin Empire, declared himself Emperor of China and founded the Yuan dynasty. Kublai renewed the Mongol campaign against the Song eventually capturing the fortified cities of Fancheng, and Xiangyang during the Battle of Xiangyang in 1273, allowing his armies to advance deep into Song territory and seize its capital. On 19 March 1279, the Song chancellor Lu Xiufu committed suicide with the eight-year-old Zhao Bing after the defeat of the remaining Song forces at the Battle of Yamen bringing an end to the Song Dynasty and marking the beginning of a century of Mongolian rule over China before the establishment of the Ming Dynasty by the House of Zhu and a return to Han rule.

Output:
b