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.

Let me give you an example: Question: A distension is defined as:
Options: <0> Soft tissue injury. <1> Forced movement of abrupt production. <2> Injury by stretching a muscle. <3> Injury of the joint capsule. <4> Interruption in the continuity of a bone.
The answer to this example can be: nursery
Here is why: Distension means Bloating and swelling in the belly area. It does not have much to do with chemistry, psychology, pharmacology, biology and medicine. Hence, the correct topic is nursery.

OK. solve this:
Question: It is very common the use of rotary valves of 6 doors or routes, alternately switchable, for the injection of samples in liquid chromatography of high resolution. Which of the following answers is correct?
Options: <0> In the injection position, the mobile phase flow is maintained towards the column without passing through the loop. <1> In the loading position, the loop in charge of housing the sample remains open to the atmosphere whereby the sample can be deposited by means of a syringe. <2> In the loading position, the mobile phase flow is maintained towards the column by previously passing through the loop. <3> In the loading position, the sample is inserted into the column without disturbing the moving phase step towards the loop. <4> In the injection position, the entire internal volume of the loop is directed to the waste while the mobile phase carries the sample.
Answer:
chemistry