A client, a gravida 3 para 2 at 35 weeks’ gestation, comes in to the antepartum clinic for a check-up. She has been experiencing backaches after standing all day at her job as a grocery clerk. Which of the following exercise would the nurse suggest to relieve backache（）
A. The pelvic tilt.
B. Squatting.
C. Stretching.
D. Walking.
