Final answer:
The second stage of labor is when the baby is delivered.
Step-by-step explanation:
The correct answer is b) Second stage of labor.
During the second stage of labor, the cervix is fully dilated and effaced, and the baby is delivered. This stage is characterized by strong contractions and the mother pushing to help expel the baby from the uterus. Once the baby is born, the third stage of labor begins, which involves the delivery of the placenta and associated fetal membranes.