You Are Taking a Lab Practical Exam, and One Station

You are taking a lab practical exam, and one station has pins in various internal structures of a bisected heart. You can orient yourself without picking up and examining the exterior of the heart because

A) the width of the external wall of the left ventricle is thicker than all the other chamber walls.
B) the ascending aorta exits from the right ventricle.
C) the width of the external wall of the right atrium is thicker than all the other chamber walls.
D) the width of the external wall of the left atrium is thicker than all the other chamber walls.
E) the width of the external wall of the right ventricle is thicker than all the other chamber walls.