Correct Answer: A

Rationale: When a client's membranes rupture, there is a risk that the umbilical cord could become compressed, affecting blood flow to the fetus. The nurse's priority action is to assess the fetal heart rate to ensure that the fetus is not in distress.

Correct Answer: C

Rationale: Vitamin B6 (pyridoxine) is often used to treat nausea and vomiting in pregnancy, including hyperemesis gravidarum, and is considered safe for use in pregnant clients.

Correct Answer: A

Rationale: Cold stress in newborns can lead to increased oxygen consumption and energy expenditure as the body tries to maintain its temperature. This can result in hypoglycemia and metabolic acidosis if not addressed. The use of a radiant warmer helps maintain the infant's body temperature, reducing the risk of cold stress and its complications.

Correct Answer: D

Rationale: The client should check for the string each month after menstruation to ensure the IUD is in place. Regular checks can help identify any displacement.

Correct Answer: D

Rationale: The nurse should assist the client into the knee-chest position to relieve pressure on the umbilical cord. This position helps to prevent cord compression and improves fetal oxygenation.