The correct answer is choice B. The cord is hidden, often next to but not in front of the fetal head. This is called an occult cord prolapse and it occurs when the umbilical cord descends alongside–but not past–the presenting part of the baby. Occult cords can occur with ruptured or intact membranes. They can cause hypoxia, brain injury, and permanent disability in a baby, so medical personnel must address them rapidly and appropriately.

Choice A is wrong because it describes an overt cord prolapse, which means that the cord slips down into your cervix and vagina ahead of your baby during delivery. This is a medical emergency that can cut off your baby’s blood and oxygen supply during delivery.

Choice C is wrong because it describes a visible cord prolapse, which is a type of overt cord prolapse where the cord is visible or palpable outside of the vagina. This is also a medical emergency that requires immediate delivery.

Choice D is wrong because it describes a nuchal cord, which means that the cord is wrapped around the fetal neck or body. This is not a prolapse, but it can cause complications such as reduced blood flow, fetal distress, or umbilical cord strangulation.