Final answer:
The MA should instruct a patient to place a protective cover, use pins if necessary, adjust the pad, and not lie on it when using a heating pad.
Step-by-step explanation:
When explaining the use of a heating pad, the MA should instruct a patient to:
A. Place a protective cover over the pad to prevent direct contact with the skin and provide a layer of insulation.
B. Use pins to secure the pad in place if necessary, to ensure it doesn't move or fall off during use.
C. Adjust the pad to a higher setting if it no longer feels warm to maintain the desired temperature and therapeutic effect.
D. NOT lie on the pad, but instead place it on the desired body part, such as the back or abdomen.
Therefore, the correct answer is E. All of the above, as all the options mentioned are important instructions to ensure safe and effective use of a heating pad.