Answer
(b) parietal pericardium/outer surface of heart
Work Step by Step
Parietal membranes line the walls of body cavities, while visceral membranes line organs within those cavities. Therefore, the visceral peritoneum does line the outer surface of the small intestine, and the parietal pleura does line the wall of the thoracic cavity. However, the parietal pericardium lines the thoracic cavity, not the outer surface of the heart.
