You have been dispatched to a residence for a female patient who is dizzy and "passing out." An Emergency Medical Responder meets you at the door and reports that the patient is lying in bed and is nine months pregnant. Her pulse rate is 112 beats per minute and her blood pressure is 84/50 mmHg. Respirations are 24 breaths per minute and she has a room air pulse oximetry reading of 97%. What should you do as soon as you reach the patient's side?

A) Recheck the blood pressure
B) Roll her onto her left side
C) Determine any complications of the pregnancy
D) Start positive pressure ventilation

B) Roll her onto her left side