Final answer:
The thoracic cavity contains the lungs and the heart, with the correct answer being lungs. So, the correct answer is option c.
Step-by-step explanation:
The thoracic cavity is a component of the anterior (ventral) cavity that contains several vital organs. Specifically, the thoracic cavity houses the lungs and the heart, the latter of which is located within the mediastinum. The thoracic cavity is separated from the abdominopelvic cavity by the diaphragm. Therefore, the correct answer to the question of what the thoracic cavity contains is lungs.
So, the correct answer is option c.