In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

Input: Consider Input: One reactant for this reaction is best prepared by an S N 2 nucleophilic addition of a triphenyl compound, followed by elimination of the hydrogen halide by an organolithium reagent. This reaction itself proceeds through a rather unique intermediate formed when the pi electron from the reagents carbon-oxygen double bond migrates to the positively charged pole of one reactant; this intermediate is called a an oxaphosphetane, from which a triphenyl oxide is eliminated to complete the reaction. The aforementioned positively charged pole is on phosphorous because the aforementioned prepared reactant is a phosphorous ylide. For ten points, name this reaction that produces selectively double-bonded alkenes from aldehydes and phosphorous ylides and that is named for the German 1979 Chemistry Nobel winner.

Output: Science

Input: Consider Input: Erwin Finlay-Freundlich proposed one explanation for this phenomenon that claimed its strength should be proportional to the radiation density. A version of this phenomenon in the CMB is known as the Sachs-Wolfe effect, while the quantity that describes the strength of this effect has a value of about 1100 for the surface of last scattering. One version of this effect was measured using the Mossbauer effect in an experiment by Pound and Rebka, and the magnitude of this effect is usually denoted "z. " For 10 points, name this phenomenon, which can be caused by gravity or the Doppler effect, in which the wavelength of an object's light appears longer to an observer.

Output: Science

Input: Consider Input: Alternating light and dark bands found at the base of these geological formations are known as ogives (OH-jives). These formations erode the surrounding terrain through processes known as plucking and abrasion. Such erosion can lead to the development of indentations known as cirques (SEERKS), which often have small lakes referred to as tarns. They form crevasses on their surface. For 10 points, name these large flows of ice.
Output: Science