An adolescent is prescribed retinoic acid cream as therapy for his acne. About which of the following would you caution him?

Rationale: A. Retinoic acid increases skin sensitivity to sunlight, so avoiding extended sun exposure is important to prevent irritation and sunburn. B. The cream should be applied directly to affected areas, not avoided. C. Applying the cream before bedtime is actually recommended to reduce sun exposure and irritation. D. The skin should be dry before application, as applying on wet skin can increase irritation, so this is also a correct caution but less critical than sun sensitivity. However, the primary caution is sun avoidance.