A nurse notices a school-age child with leukemia experiencing severe nausea and vomiting when receiving chemotherapy for the first time. Which is the most appropriate nursing action to prevent or minimize these reactions with subsequent treatments?

A. Administering an antiemetic only when the child complains of nausea may not be effective in preventing chemotherapy-induced nausea. B. Encouraging drinking fluids is important, but it is not the most effective way to manage nausea. C. Administering an antiemetic before chemotherapy begins is the best approach to prevent nausea and vomiting associated with chemotherapy. D. Skipping meals may contribute to nausea and malnutrition, so this is not an appropriate approach.