With Regard to the Position of the Laboring Woman, Maternity

With regard to the position of the laboring woman, maternity nurses should be able to tell the woman that:

A) The supine position commonly used in the United States increases blood flow.
B) The "all fours" position, on her hands and knees, is hard on her back.
C) Frequent changes in position will help relieve her fatigue and increase her comfort.
D) In a sitting or squatting position her abdominal muscles will have to work harder.