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.

[EX Q]: 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.
[EX A]: Science

[EX Q]: The highest point of this city is the Hermannskogel. A 20-ton bell made from captured Turkish cannons can be found in this city's St. Stephen's Cathedral. This city's chief park, the Prater, is known for its giant Ferris wheel. This city is home to the Ringstrasse (RING-strah-suh), on which stands the Rathaus. This city is the headquarters for the International Atomic Energy Agency and OPEC, and this city is located on the Danube River. For 10 points, name this capital of Austria.
[EX A]: Social Science

[EX Q]: Motivated by an account of a family dying when the seal on their refrigerator ruptured, this man and Leo Szilard patented a refrigerator that cooled using only heat as input. A model of the universe that is isotropic and homogeneous with zero curvature and zero cosmological constant is named for him and (*) de Sitter, while the rule that a repeated index in an expression is meant to be summed over every possible value of that index is known as his summation convention. Winning the 1921 Nobel Prize in Physics for his "discovery of the law of the photoelectric effect," for 10 points, name this physicist also known for his development of the theories of general and special relativity.
[EX A]:
Science