Q: 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: When we inject 1 nanoliter (nL) sample we are referring to the injection of: 
 Options:  <0> 10-1 L. <1> 10-3 L. <2> 10-6 L. <3> 10-9 L. <4> 10-12 L.
A:
chemistry