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.

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.
Science

In plasmas, the ambipolar version of this phenomenon is inversely proportional to the collision frequency, while the classical form is directly proportional, and is a random-walk process. A semi-empirical formula can be used to describe the Bohn version, while classical cases are governed by Fick's laws and Graham's law. FTP, what is this process in which gases mix due to the random motions of their molecules
Science

The Orthodox Christian saint Josaphat was said to be one of these, and his name is a distortion of the word used to designate them. A 500-foot-tall statue is being built in Kushinagar in honor of one named Maitreya, who some believe will come after the teachings of Shakyamuni disappear. To become one, it is necessary to master the six perfections, after which you choose to be either one of these or an Arhat. Those such as the Avalokiteshvara and the 14th Dalai Lama who chose to stay behind and help others on their path to Nirvana are known by, FTP, what term used in Mahayana Buddhism that literally means "wise being"

Social Science