Why Were There Not That Many Fossils Until Teeth and Bones

Why were there not that many fossils until teeth and bones appeared in fossil finds?

A) Hard tissues lend themselves to mineral fossilization, while soft tissues are usually fossilized as moulds.
B) Soft tissues lend themselves to mineral fossilization, while hard tissues are usually fossilized as moulds.
C) Hard and soft tissues are both fossilized as moulds.
D) Hard and soft tissues both lend themselves to mineral fossilization.