You will be given a definition of a task first, then some input of the task.
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.

This material loses effectiveness after an action called girdling, which leads to tissue death. Ernst Munch proposed that this material works via the pressure flow hypothesis. This material consists of parenchymal, sieve-tube, and companion cells. In trees, this material is found in the inner bark, which is why its name derives from the Greek for ""bark. "" (*) For 10 points, name this living vascular material that transports nutrients within a plant, contrasted with the water-carrying xylem.
Output:
Science