The nurse is planning a class about blood glucose monitoring for a group of clients with diabetes mellitus. Which timing of glucose testing would apply for any client regardless of the client's age or type of diabetes?

A. Prior to exercising: Testing before exercise is important, especially for clients on insulin, but may not be necessary for all clients depending on their diabetes management and regimen. B. Before going to bed: This is often recommended for insulin-dependent diabetics to avoid nocturnal hypoglycemia, but it's not universally required for all clients. C. Immediately after meals: Postprandial glucose testing is useful, especially for gestational diabetes or insulin adjustments, but it is not routinely required for all diabetics. D. During acute illness: All clients with diabetes should monitor blood glucose more frequently during illness, as stress hormones can cause hyperglycemia or unexpected hypoglycemia.