A nurse is reviewing guidelines to prevent diabetic ketoacidosis (DKA) during periods of illness with a client who has type 1 diabetes mellitus. Which of the following instructions should the nurse include in the teaching?

Check your urine for ketones when blood glucose levels are greater than 240 mg/dL.

Drink 240 to 360 milliliters of calorie-free liquids every 8 hours.

Test your blood glucose level every 8 hours.

Withhold your usual daily dose of insulin.