The drug mainly causing afterload reduction is:
High-Yield Explanation
ACE inhibitors are mixed dilators. They inhibit the generation of angiotensin II resulting in dilatation of aerioles which decreases peripheral vascular resistance and thereby after load. Nitrates are primarily venodilators- decrease Cardiac output mainly calcium channel blockers are mainly aeriolar dilators -decreases peripheral vascular resistance by causing vasodilatation (Ref- ESSENTIAL OF MEDICAL PHARMACOLOGY-K.D TRIPATHI)