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

Input: Consider 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.

Output: optical effect


Input: Consider Input: The expansion of what further cemented Houston's emergence as a powerhouse commercial city?, Context: By 1860, Houston had emerged as a commercial and railroad hub for the export of cotton. Railroad spurs from the Texas inland converged in Houston, where they met rail lines to the ports of Galveston and Beaumont. During the American Civil War, Houston served as a headquarters for General John Bankhead Magruder, who used the city as an organization point for the Battle of Galveston. After the Civil War, Houston businessmen initiated efforts to widen the city's extensive system of bayous so the city could accept more commerce between downtown and the nearby port of Galveston. By 1890, Houston was the railroad center of Texas.

Output: bayous


Input: Consider Input: Things related to an ancient religious movement that originated in France and rejected ultramontanism is called?, Context: Among the paleo-orthodox and emerging church movements in Protestant and evangelical churches, in which some Presbyterians are involved, clergy are moving away from the traditional black Geneva gown to such vestments as the alb and chasuble, but also cassock and surplice (typically a full length Old English style surplice which resembles the Celtic alb, an ungirdled liturgical tunic of the old Gallican Rite), which some, particularly those identifying with the Liturgical Renewal Movement, hold to be more ancient and representative of a more ecumenical past.


Output: Gallican