Definition: 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.
Input: Question: To observe the bacterial capsules in a clear field microscope, a stain is made: 
 Options:  <0> Resistant acid <1> From Leifson. <2> Simple. <3> Negative. <4> Differential.
Output:
biology