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.

When these devices exploit their voltage-dependent variable capacitance they are known as varactors. Barring the creation of local hot spots, a non-destructive avalanche current is produced by electron-hole pair propagation when the electric field within the (*) depletion region of these devices reaches a critical value. Majority carriers exist in an energy state greater than the Fermi energy in the Schottky barrier variety and those that operate in reverse breakdown are named after Zener. For 10 pointsname these devices that allow current to pass in only one direction.
Science

In one work of this composer, a "drinking chorus" is preceded by tone painting of the baying of hounds via double grace notes in the strings, trombones, and horns, which directly quote hunting calls. In another of his works, C minor is associated with the Vorstellung, and the keys of B-flat and E-flat are representative of humanity. His other religious works include his "Great Organ" Mass and the somewhat programmatic Mass in Distress and Mass in Time of War. His Trumpet Concerto in E-flat Major written for Anton Weidiger was one of the few to be written for the keyed trumpet, and his Opus 20 group of six string quartets is commonly referred to as the "Sun" Quartets. His symphonies include one whose first movement's second theme in B-flat imitates a clucking of a chicken and one which instructs the musicians to leave as they complete their parts during the last movement. FTP, name this Austrian composer of the "Farewell" Symphony, the Paris Symphonies, and the London Symphonies, which include the "Surprise".
Fine Arts

A 2000 study by P. F. Coogan, et al. states that this chemicalis found to be genotoxic and can bind to estrogen receptors. It is usually synthesized in the presence of zinc chloride or sulfuric acid by the condensation of its namesake (*) anhydride and phenol, and is closely related to triphenylmethane. One of its forms has a charge of negative three due to the removal of two extra hydrogen ions, and occurs only in solutions with pH greater than 12, and in solutions with pH less than 0, it appears orange. It was at one point used as a laxative, where it dyed feces pink. For 10 points, identify this indicator, which is colorless in acids and pink in bases.

Science