Final answer:
Human chorionic gonadotropin (hCG) functions as a placental hormone during pregnancy, essential for maintaining progesterone production and stimulating testosterone secretion in male fetuses.
Step-by-step explanation:
The hormone in question, often referred to as Chronic Gonadotropin, is most likely human chorionic gonadotropin (hCG), which functions as a placental hormone during pregnancy. Its primary roles include promoting the survival of the corpus luteum, which is crucial early on in pregnancy for maintaining the production of progesterone, and stimulating the male fetal gonads to secrete testosterone, which is essential for the development of the male reproductive system. Thus, the correct answer to the student's question is c) A placental hormone.