Instructions: 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.
Input: Question: Regarding the phases of the clinical development of a drug, which of the following characteristics does NOT correspond to a clinical trial in phase 2?
Options: <0> They are exploratory therapeutic studies. <1> They are performed in a large number of patients (between 100 and 1000). <2> They are used to delimit a range of therapeutic doses. <3> The informed consent of the patients is required for their inclusion in the study. <4> They are usually of short duration.
Output:
medicine