45 yo M evaluated during a second follow up visit after hospitalization for new-onset heart failure with reduced EF. EF at time of diagnosis 2 months ago was 42%. He reports feeling better with improving exercise tolerance and no exertional dyspnea.What is the most likely reason for the improvement in exercise tolerance and absence of exertional dyspnea in the patient?
a) Increased cardiac output
b) Decreased pulmonary vascular resistance
c) Improved skeletal muscle strength
d) Reduced myocardial oxygen demand
