After cancer chemotherapy, a client develops nausea and vomiting. For this client, the nurse should give the highest priority to which action in the plan of care（）
A. Serve small portions of bland food.
B. Encourage rhythmic breathing exercise.
C. Administer metoclopramide (Reglan) and dexamethasone (Decadron) as prescribed.
D. Withhold fluids for the first 4 to 6 hours after chemotherapy administration.
