Answer:
A. Superior vena cava
B. Right pulmonary veins
C. Can't see where's that pointing at
D. Right atrium
E. Tricuspid valve
F. Right ventricle
G. Inferior vena cava
H. Looks like a muscle but I don't know the specific name
I. Left ventricle
J. Mitral/bicuspid valve
K. Aortic valve
L. Left atrium
M. I don't know
N. Left pulmonary veins
O. Aorta