Q: 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: A group of researchers conducted a prospective study to evaluate the efficacy of three alternatives in the treatment of acute otorrhea in children with tympanostomy tubes. Randomized, 76 children received oral amoxicillin-clavulanic acid, 77 received ear drops with hydrocortisone-bacitracinacolistin and other 77 children did not receive any pharmacological treatment, only observation. The main variable was the presence of otorrhea. What kind of study is it?
Options: <0> Cohort study. <1> Post-authorization study of prospective follow-up. <2> Post-authorization study linked to the authorization. <3> Clinical trial <4> Transversal study.
A:
medicine