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.

This man achieved full power within his party at the Zunyi Conference. That conference occurred while this man and other members of his party were traveling from Jiangxi (jee-AHNG-shee) to Yanan as part of the Long March. This leader's third wife was part of an influential group that was named the Gang of Four. This ruler was responsible for his country taking part in the (*) Great Leap Forward and the Cultural Revolution. For 10 points, name this political rival of Chiang Kai-shek who was the first leader of Communist China.
History

The reciprocal relationship between the eigenvalues of the mass matrix of these particles is called the "seesaw mechanism"; the larger eigenvalue may be the mass of their "sterile" variety. One phenomenon predicted by Pontecorvo involving these entities was searched for by (*) MINOS. Reines and Cowan used an aqueous cadmium chloride solution to detect them, and other detectors tend to include large volumes of material, such as Super Kamiokande. For 10 points, name these leptons, the nearly massless products of radioactive decay whose varieties include the muon and tau and which are represented by the letter nu.
Science

The Gibbs paradox deals with a faulty derivation of this quantity which erroneously suggests it is not an extensive variable. For a monatomic ideal gas, its value is given by the Sackur-Tetrode equation, while for a black hole it is proportional to the surface area of the event horizon. In general it is equal to Boltzmann's constant times the natural logarithm of the number of accessible states. According to the Second Law of Thermodynamics, it always increases in irreversible processes. Proposed by Rudolf Clausius and symbolized S, FTP, what is this measure of the disorder in a system

Science