The external cephalic version is commonly used to manage:

Correct option is B

External cephalic version (ECV) is a manual procedure performed after 36 weeks of gestation to turn a fetus from breech to cephalic (head-down) presentation to allow for normal vaginal delivery. It is a safe and effective alternative to cesarean section in suitable candidates. The procedure requires ultrasound guidance and monitoring.
Explanation of options: (a) ✘ Anencephaly – A neural tube defect with absence of major brain parts; not managed by ECV. (b) ✔ Breech presentation – ECV is specifically used to convert breech fetuses into a head-down position. (c) ✘ Placenta previa – A placental placement issue where vaginal delivery is contraindicated; ECV is not used. (d) ✘ Hydrocephalus – A neurological condition involving cerebrospinal fluid accumulation; not related to fetal positioning.