In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Example Input: What is Rayleigh scattering?, Context: In nature, the red color of blood comes from hemoglobin, the iron-containing protein found in the red blood cells of all vertebrates. The red color of the Grand Canyon and other geological features is caused by hematite or red ochre, both forms of iron oxide. It also causes the red color of the planet Mars. The red sky at sunset and sunrise is caused by an optical effect known as Rayleigh scattering, which, when the sun is low or below the horizon, increases the red-wavelength light that reaches the eye. The color of autumn leaves is caused by pigments called anthocyanins, which are produced towards the end of summer, when the green chlorophyll is no longer produced. One to two percent of the human population has red hair; the color is produced by high levels of the reddish pigment pheomelanin (which also accounts for the red color of the lips) and relatively low levels of the dark pigment eumelanin.
Example Output: optical effect

Example Input: Einstein created a way of thinking called a?, Context: It was only the orbit of the planet Mercury that Newton's Law of Gravitation seemed not to fully explain. Some astrophysicists predicted the existence of another planet (Vulcan) that would explain the discrepancies; however, despite some early indications, no such planet could be found. When Albert Einstein formulated his theory of general relativity (GR) he turned his attention to the problem of Mercury's orbit and found that his theory added a correction, which could account for the discrepancy. This was the first time that Newton's Theory of Gravity had been shown to be less correct than an alternative.
Example Output: theory

Example Input: What succeeded the Mesolithic period?, Context: The Mesolithic period in the Indian subcontinent was followed by the Neolithic period, when more extensive settlement of the subcontinent occurred after the end of the last Ice Age approximately 12,000 years ago. The first confirmed semipermanent settlements appeared 9,000 years ago in the Bhimbetka rock shelters in modern Madhya Pradesh, India. Early Neolithic culture in South Asia is represented by the Bhirrana findings (7500 BCE) in Haryana, India & Mehrgarh findings (7000–9000 BCE) in Balochistan, Pakistan.
Example Output:
the Neolithic period

