You will be given a definition of a task first, then some input of the task.
In this task, you are given a question and answer options for that question. Using this information, you have to classify each text into different topics: medicine, nursery, psychology, chemistry, pharmacology, biology.

Question: The microvilli contain a beam of: 
 Options:  <0> Microtubules <1> Actin filaments. <2> Intermediate filaments <3> Spectrine <4> Collagen fibers.
Output:
biology