Final answer:
The most common reason for performing a cesarean hysterectomy is placenta previa.
Step-by-step explanation:
The most common reason for performing a cesarean hysterectomy is a) Placenta previa. Placenta previa occurs when the placenta partially or completely covers the opening of the cervix. It is the leading cause of antepartum hemorrhage and may require a cesarean hysterectomy for the safe delivery of the baby.