Detailed Instructions: 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.
Problem:Question: The clinical sensitivity of an analytical parameter (test) is defined as: 
 Options:  <0> The mean concentrations of this test in healthy patients. <1> A pathological concentration of the test in the presence of the disease. <2> A pathological concentration of the test in the absence of the disease. <3> A normal concentration of the test in the absence of the disease. <4> A normal concentration of the test in the presence of the disease.
Solution:
chemistry