A nurse is providing teaching to a client who has a new prescription for insulin glargine. Which of the following instructions should the nurse include?

The correct answer is C: Administer the insulin at bedtime. Insulin glargine is a long-acting insulin that is typically administered once daily at the same time each day, often at bedtime. This timing helps provide a consistent basal insulin level throughout the night, mimicking the body's natural insulin release pattern. Option A is incorrect as rotating injection sites is recommended to prevent lipohypertrophy. Option B is incorrect as insulin glargine should not be shaken vigorously to avoid damaging the insulin molecules. Option D is incorrect as insulin glargine should appear clear, not cloudy.