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.

[EX Q]: Question: To measure the pulmonary wedge pressure (PEP) by means of a pulmonary artery catheter, it is advisable to take into account that: 
 Options:  <0> It is not necessary to inflate the ball. <1> The catheter should always be inserted with the balloon inflated, but at half the recommended volume. <2> The volume of balloon inflation is usually 1.5 ml of air. <3> The volume of inflation of the balloon is usually 3 ml of air. <4> You have to leave the balloon always inflated after making the determinations of PEP.
[EX A]: nursery

[EX Q]: Question: Which of the following is currently the only contraindication for conservative surgical treatment in breast cancer? 
 Options:  <0> Prior radiotherapy. <1> Tumor of 4 cm. <2> Axillary metastasis. <3> Multifocal tumor <4> Pregnancy of 32 weeks.
[EX A]: medicine

[EX Q]: Question: What does the intersessional sampling used in observation techniques refer to: 
 Options:  <0> To the registration of relevant information between sessions. <1> To the periodicity, number and criteria of start-end of the sessions. <2> To the successive rounds of observation of the subjects to observe. <3> To the temporary selection and its interval or partial modality. <4> To the record of focal events that occur between sessions.
[EX A]:
psychology