The prescriber tells a patient with allergies to use oral diphenhydramine (Benadryl) ...

The prescriber tells a patient with allergies to use oral diphenhydramine (Benadryl) over-the-counter (OTC) to help manage her symptoms. She tells you that she would rather have a prescription for the real Benadryl
 
  because she knows it is stronger and will work better than the nonprescription form. What is your best response?
  a. If you receive a prescription for this drug your name will be added to a controlled substances list.
  b. It is better to use the OTC Benadryl rather than the prescribed form because it has fewer side effects.
  c. The OTC form of Benadryl is the same strength as the one that was available by prescription only.
  d. You are correct. I will ask the health care provider to write a prescription so that you can get the most effective drug.