Given the task definition and input, reply with output. 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: In the context of the analysis of the factors that influence the outcome of psychotherapy, state which of the following can be considered a specific (technical) factor (versus other types of factors, such as, for example, extra-therapeutic change, common factors):
Options: <0> Placebo effect. <1> Promote successful experiences in the course of therapy. <2> Establishment of a relationship of trust. <3> Use of empathy. <4> The economy of chips.
psychology