Questions: The inner most lining encasing the lungs is the: a. Pericardial sac. b. Parietal pleura. c. Visceral pleura. d. Visceral peritoneum

The answer is the third one (c): Visceral pleura.

Explanation for each option:

a. Pericardial sac: This is incorrect. The pericardial sac is the double-walled sac containing the heart and the roots of the great vessels. It is not related to the lungs.

b. Parietal pleura: This is incorrect. The parietal pleura is the outer layer of the pleura that lines the thoracic cavity and is not directly attached to the lungs.

c. Visceral pleura: This is correct. The visceral pleura is the innermost lining that directly covers the lungs. It is a thin membrane that adheres to the surface of the lungs.

d. Visceral peritoneum: This is incorrect. The visceral peritoneum is the inner layer of the peritoneum that covers the abdominal organs, not the lungs.

In summary, the visceral pleura is the innermost lining encasing the lungs.