A nurse in a health care provider's office teaches a patient how to apply an occlusive dressing (using plastic film) to cover a medicated ointment applied to her arm. An important teaching point would be to tell the patient to:

a) Apply the ointment thickly under the dressing
b) Change the dressing every 3 hours
c) Wrap the dressing tightly to promote absorption
d) Leave the edges of the dressing loose to allow airflow