Which of the following are true regarding the crust of the earth?
I. It is the outer thin layer with a total thickness of about 100 km
II. It forms around 0.5% of the earth's volume
III. The outer covering of the crust is of sedimentary material
IV. The lower layer of the crust consists of basaltic and ultra-basic rocks

A. I and II

B. I, II and III

C. I, II and IV

D. I, II, III and IV

Answer: Option C