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.
Q: Question: By what name is the disorder known to be characterized by the constant and persistent repetition of words, ideas, or themes, to which the patient continually appeals ?:
Options: <0> Perseveration of thought. <1> Divagatory thinking. <2> Disintegration of thought. <3> Circumstantiality <4> Inhibition of thought.
A:
psychology