【单选题】

To obtain a good monitor tracing on a client in labor, the mother lies on her back. Suddenly, she complains of feeling light-headed and becomes diaphoretiC、Which of the following should be the nurse’s first action

A、Reposition the client to her left side.
B、Immediately take the client’s blood pressure and call the physician.
C、Start oxygen at 6 L via nasal cannulA、
D、Increase the IV fluids to correct the client’s dehydration.