A nurse is caring for a client who is in labor, just received spinal anesthesia, and is experiencing hypotension. Which of the following actions should the nurse take?

A. Administer oxygen via nasal cannula at 2 L/min: Oxygen may support maternal and fetal oxygenation, but it does not treat the underlying cause of hypotension following spinal anesthesia. It is a supportive measure, not the first-line intervention. B. Place the client in a knee-chest position: This position is not recommended for treating hypotension due to spinal anesthesia. The priority is to improve perfusion through fluid resuscitation and positioning that enhances venous return, such as left lateral tilt. C. Assist the client to the bathroom: Ambulation is unsafe for a client experiencing hypotension after spinal anesthesia and could worsen hypotension or cause falls. The client should remain supine or in a safe position until blood pressure is stabilized. D. Give 500 mL bolus of lactated Ringer's: Administering a rapid IV fluid bolus is the first-line intervention for hypotension related to spinal anesthesia. It increases intravascular volume, improves venous return, and helps restore blood pressure to maintain maternal and fetal perfusion.