Final answer:
Parturition is the process of childbirth (option a) , which includes three main stages: dilation of the cervix, birth of the baby, and delivery of the placenta (afterbirth). Labor usually begins within a week of the due date, unless there are factors such as multiple pregnancies that may cause an earlier start.
Step-by-step explanation:
Parturition is the process of childbirth. This biological event typically occurs within a week of the woman's due date, although variations such as preterm labor or multiple pregnancies can alter this timing. The process of labor is generally divided into three stages: cervical dilation, expulsion of the newborn, and delivery of the afterbirth (placenta and associated membranes). During the first stage, the cervix thins and dilates to prepare for the baby's passage. In the second stage, the baby is expelled from the uterus.
The final stage involves the delivery of the placenta, marking the beginning of the postpartum period. It is important to note that lactation refers to milk production for breastfeeding, while afterbirth specifically denotes the delivery of the placenta after the baby has been born, and preterm describes childbirth that occurs before 37 weeks of gestation.