Final answer:
The structure that contains the heart is the pericardium, made up of fibrous and serous layers, and the correct answer is B) Pericardium.
Step-by-step explanation:
The sac-like, multi-layered anatomic structure that contains the heart is called the pericardium or pericardial sac. This vital structure separates the heart from other mediastinal structures and consists of two distinct, fused sublayers: the fibrous pericardium and the parietal pericardium. The fibrous pericardium is a sturdy layer made of tough, dense connective tissue that protects the heart and maintains its position in the thorax. The inner serous pericardium consists of two parts: the parietal pericardium, which is fused to the fibrous pericardium, and the visceral pericardium, or epicardium, which covers the heart itself. The pericardial cavity between these layers contains lubricating serous fluid to reduce friction during heartbeats. Therefore, the answer to the question is B) Pericardium.