Which of the following tissues lines the interior structures of the heart?
A. Epicardium
B. Pericardium
C. Myocardium
D. Endocardium
The endocardium lines the interior structures of the heart. It is a thin, innermost layer of the heart wall that lines the heart chambers and valves. It is composed of subendocardial connective tissue and endothelial cells that are continuous with blood vessel endothelium.
Therefore, the Correct Answer is D.