Which statement applies only to the axial skeleton, not the appendicular skeleton?

The correct statement is "It protects the heart and lungs".

Explanation:

Axial skeleton in our body is responsible to protect the heart and lungs. Appendicular skeleton have nothing to do with the protection of heart and lungs, because it only covers the upper and lower part of our limbs not the middle part where heart and lungs are present. This middle portion is covered by the axial skeleton. The number of axial bones in human is 80 in total.