NEED HELP BAD PLEASE HELP In what way are the humerus and the femur similar?

an x-ray of the human body showing the humerus and femur bones

A.
They both attach their respective limbs to the axial skeleton.
B.
They both have similar joints at each end.
C.
They both are extremely strong and made only of compact bone.
D.
They both have hollow spaces filled with bone-generating cells.
E.
They both protect vital organs.