Teacher: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.
Teacher: Now, understand the problem? Solve this instance: Extant classes of this phylum of animals include Crinoidea and Stelleroidea. They have a simple nervous system consisting of nerve rings, a rudimentary circulatory system, and no brain, and movement is achieved using a rounded muscular sac called an ampulla. Unique in their posession of a water vascular system and tube feet, their spiny skin gives them their name, and many of them have pentaradial symmetry. FTP, name this phylum which includes sea cucumbers, sea urchins, and starfish.
Student:
Science