Final answer:
Oxytocin is the drug given to aid in placental expulsion during labor.
Step-by-step explanation:
Oxytocin is the drug given to aid in placental expulsion during labor. Oxytocin is a hormone that is primarily responsible for the contractions during labor. It causes the smooth muscle in the uterine wall to contract, helping in the expulsion of the baby and placenta from the uterus. Synthetic oxytocin can be administered if labor stops before the placental expulsion.