Answer:
The correct answer is C. The medial surface of the left lung exhibits a concavity called Cardiac Notch.
Step-by-step explanation:
The two lungs are not of equal size because the heart is located somewhat oblique, with its apex slightly to the left of the middle plane of the body, which forces the left lung to have a concavity in its medial aspect to accommodate the apex of the heart, resulting smaller than the right lung. The cavity in the left lung that houses the apex of the heart is called the cardiac notch.