Answer:
Type of Study: Retrospective Cohort Study.
Explanation:
In case a. the study design that is used is the Retrospective Cohort Study. In a Retrospective Cohort Study, a group of individuals who were exposed to a given factor is compared to another group of individuals who were not exposed to that given factor to study the factor's incidence in a disease. In case a. women who had just delivered an infant with a cleft lip and women who had just delivered an infant without any birth defects. These two groups were interviewed to determine if they took antidepressant medication during pregnancy. The study measured the effects of antidepressant medication on their offsprings. The effect of antidepressant medication during pregnancy and the presence or absence of cleft lip in the newborn.