Answer:
The correct answer is option D.
Step-by-step explanation:
The fossils are formed only when the plants and animals are buried in the watery environment due to the deposition of mud, sand, silt and clay which forms rock after millions of years. The fossils are not formed from the soft parts but from the hard parts of the organisms.
Fossilization of leaves takes place due to a process called "carbonization' in which the volatile substance of plants and animals are lost but leave behind a carbon film. Due to carbonization, the anatomy of the leaf is lost but cell content and cell wall are preserved.
Thus, option D is the correct option.