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.

[Q]: Lin and Shu proposed the density-wave theory to explain how the structure of these entities is sustained. The most accurate method for measuring the distances to distant ones uses a relation between their maximum rotational velocity and absolute magnitude, which is known as the Tully-Fisher method. They are generally blue because of their high content of old stars, and one type of them features arms that emanate from each end of a namesake structure. They have discs like the lenticular type, but contain much more angular momentum than the elliptical type. FTP name these galaxies, some of which are barred, including the Milky Way.
[A]: Science

[Q]: It is not serotonin, but the selective reuptake of this compound is inhibited by tiagabine, and it is converted to succinic acid semi-aldehyde, which is subsequently oxidized to succinic acid in the shunt which produces this compound. One receptor for it forms a heteropentameric complex and in immature neurons, this compound facilitates the outward flux of chloride ions, which is why benzodiazepines are ineffective anticonvulsants in newborns. One receptor for it includes a benzodiazepine binding site, and isoguvacine THIP, and muscimol serve as competitive agonists to this molecule. Synthesized by the decarboxylation of glutamic acid, this neurotransmitter is best known for its role as the chief inhibitory neurotransmitter. For 10 points, identify this neurotransmitter, which is often referred to by its four letter acronym.
[A]: Science

[Q]: The ISIS and SNS facilities produce these particles using spallation, and a nonzero electric dipole moment would imply the violation of CPT theorem. Certain objects composed of these particles obey the Tolman-Oppeheimer-Volkov limit, whose antiparticle having a mass of 940 MeV was discovered by Bruce Cork. When free, this particle has a lifetime of about 15 minutes and decays into an antineutrino, an electron and a proton, and it is a baryon made up of two down quarks and one up quark. Discovered by James Chadwick, for 10 points, identify this neutral subatomic particle.
[A]:
Science