Task: Text Categorization
Input (English): Question: A study is being conducted in a health center to determine the effect of exposure to tobacco smoke in children of smoking parents. For this purpose, a group of healthy children between 3 and 7 years old whose parents are smokers is selected and at the same time an equal number of children whose parents are non-smokers are selected in the same center. A year later, the appearance of respiratory diseases during that year will be investigated in both groups. Indicate the correct answer: 
 Options:  <0> The study design is a prospective cohort. <1> The study design is cases and controls. <2> The study design follows a qualitative methodology. <3> The study is experimental. <4> The type of design used is efficient to study rare diseases.
Output (English): medicine