what happens to soft parts of organisms when cast fossils form?\no they decay.\no they petrify.\no they form…

Brief Explanations:

When cast fossils form, the soft parts of organisms are not preserved in - tact. They decay away, leaving behind a cavity that can later be filled with sediment to form a cast fossil. Petrification is the process of organic material turning into stone - like material, which is not what happens to soft parts during cast fossil formation. Carbon films are thin, carbon - rich films left by the decay of organisms, but this is not the main fate of soft parts in cast fossil formation. Soft parts do not become part of the cast fossil as they decay.

Answer:

They decay.