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: An important test to distinguish Staphylococcus aureus from saprophytic staphylococci, such as Staphylococcus epidermidis is: 
 Options:  <0> Oxidase <1> Catalase <2> Indole. <3> Urea <4> Coagulase
Output:
biology