56-year-old woman

56-year-old woman with chronic, stable angina and a previous myocardial infarction is treated with an oral drug that reduces the inward flow of calcium , thereby decreasing excitation-contraction coupling in the heart and vasculature resulting in dilation of coronary and systemic arteries and improving oxygen delivery to myocardial tissue. This patient is most likely treated with which of the following drugs?
Choose one answer. a. bisoprolol
b. diltiazem 
c. nadolol
d. hydralazine
e. nitroglycerin