JB is a 67 year-old man who works as a driller in the oil fields, has a history of coronary artery disease (CAD) and has developed tachycardia. He has a history of asthma and is a chronic smoker. Which of the following medications would be the most appropriate to lower his heart rate?propranololA. ClonidineB. metoprololC.DobutamineD. Prazosin