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.

The yield of these compounds can be increased through ball milling of some of their components, and one mode of operation of these compounds proceeds through a mechanism called enantiomorphic site control. A process for the operation of these compounds that proceeds through migratory insertions and obeys the "principle of least nuclear motions" was developed by Cossee and Arlman. Compounds such bis(cyclopentadienyl)titanium chloride and bis(indenyl)zirconium dichloride, known as metallocenes, have been developed as an alternative to the traditional compounds of this type. Those traditional initiators include vanadium trichloride and triethylaluminum, and the product of the application of these compounds to alkenes can result in syndiotactic, isotactic, or atactic products. For ten points, identify these stereoselective compounds used to initiate polymerization, named for a German and an Italian chemist.
Science

Aleksandr Benckendorff was charged with hunting them down, and many had been members of the Union of Salvation and the Union of Welfare. Five of them were officially executed including Pavel Pestel who organized the Southern Society and the poet Kondraty Ryelev who hoped that his Northern faction's refusal to support Nicholas I's ascension would spark an uprising that would leave Prince Trubestkoy as dictator. FTP identify this mostly upper-class group of Russian revolutionaries whose 1825 rebellion failed and who are named for the month in which their aborted operations took place.
History

This man's last work was a lecture series that included a discussion of "Galileo's Mathematization of Nature," and was later collected as The Crisis of European Sciences. Gottlob Frege notably criticized this thinker's psychological treatment of mathematics in his first published work entitled Philosophy of Arithmetic, and after studying under Thomas Masaryck, this man began to extend the ideas of Franz Brentano, a move which led to his development of the technique of epoche, or bracketing. A critique of psychologism in philosophy is contained in this man's "Prolegomena to Pure Logic," which forms the first volume of his most famous work, the volumes of which address topics such as intentionality and cognition. For ten points, identify this founder of phenomenology and author of Cartesian Meditations and Logical Investigations. 

Social Science