A patient is taking a beta-adrenergic antagonist medication for angina pectoris and asks the nurse how the drug works to relieve the discomfort associated with this condition. Which statement by the patient after the nurse’s teaching indicates understanding of the drug’s effects?a. "It causes bronchodilation, which increases oxygen flow."b. "It helps reduce the heart’s oxygen needs."c. "It improves blood flow to the heart."d. "It increases cardiac output."