Which of the following is a contraindication for vaginal delivery?

Placenta previa is indeed a contraindication for vaginal delivery because this condition involves the placenta partially or completely covering the cervix. If labor were to start, it could lead to significant bleeding, putting both the mother and the fetus at risk. As the cervix dilates during labor, the placenta could be torn away, leading to complications that are dangerous for both the mother and the baby.

In contrast, while a previous cesarean delivery may influence the mode of delivery, many women with this history can still attempt a vaginal birth, particularly if they have a low transverse incision. Multiple gestation can present challenges and may sometimes require a cesarean delivery, but it does not uniformly contraindicate vaginal delivery in all cases. Lastly, gestational hypertension may require closer monitoring and could lead to delivery via cesarean in severe cases, but it is not an absolute contraindication for vaginal delivery in itself. Therefore, placenta previa stands out as a clear reason to avoid vaginal delivery.