The Patient Receives Verapamil (Calan)

The patient receives verapamil (Calan) . The patient asks the nurse if it is okay to take herbal supplements with this medicine. What is the best response by the nurse?

A) "Using herbal supplements may increase your blood pressure too much."
B) "Herbal supplements are okay as long as you take calcium salts with them."
C) "Using herbal supplements may lower your blood pressure too much."
D) "Most herbal supplements are okay, but you should avoid St. John's wort."