Which of the following is true concerning the drug therapies used to treat heart failure? A. Beta-blockers improve ejection fraction by lowering heart rate. B. Aldosterone blockers are the mainstay of...

Which of the following is true concerning the drug therapies used to treat heart failure?

A. Beta-blockers improve ejection fraction by lowering heart rate.

B. Aldosterone blockers are the mainstay of therapy.

C. Digoxin effects the renin-aldosterone mechanism.

D. Angiotensin converting enzyme inhibitors improve myocardial contractility.