What Gives the Long Bones of Our Arms and Legs

What gives the long bones of our arms and legs their strength, and allows them to resist both compressional and bending forces?

A) Their shaft is a tube of primarily compact bone.
B) Their extracellular matrix contains crystals of calcium carbonate.
C) Their extracellular matrix consists mostly of collagen and polysaccharides.
D) They have a high density of osteoclasts.
E) They consist of lightweight cancellous bone with an internal meshwork of supporting elements.