Among the following statements, which best explains the primary pathophysiology of restrictive cardiomyopathy?

Restrictive cardiomyopathy is characterized by ventricular stiffness, diastolic dysfunction, impaired filling, and reduced compliance leading to elevated filling pressures and preserved systolic function with progressive congestive symptoms clinically progressive disease state. Rationale: A. This describes hypertrophic cardiomyopathy rather than restrictive physiology pattern present. Primary issue in restrictive cardiomyopathy is diastolic filling impairment dominant. Outflow obstruction is not defining feature of disease process here. Ventricular stiffness limits compliance causing elevated filling pressures clinically significant. B. Valve stenosis represents valvular heart disease rather cardiomyopathy pathology type. Restrictive cardiomyopathy involves myocardial compliance abnormality not valves directly affected. Backflow is consequence of valve dysfunction rather ventricular stiffness pathology. Pathophysiology centers on filling impairment not structural stenosis mechanism here. C. This describes dilated cardiomyopathy characterized by systolic dysfunction pattern noted. Restrictive disease preserves ejection fraction despite impaired filling physiology present. Ventricular enlargement is absent in restrictive cardiomyopathy clinical distinction key. Primary defect is diastolic stiffness not contractile failure mechanism basis. D. Restrictive cardiomyopathy is defined by ventricular stiffness and impaired relaxation. This leads to diastolic dysfunction with reduced ventricular filling capacity. Systolic function is often preserved in early stages clinical course. Resulting elevated pressures cause congestion and exercise intolerance progressively worsening