Each of the following is true of enamel EXCEPT one.Which one is the EXCEPTION?

A) Enamel is the hardest structure of the body.
B) Enamel is developed from the inner enamel epithelium,which is derived from mesoderm.
C) Enamel is about 96% inorganic.
D) Enamel structure is composed of the rod sheath and enamel rod.