Answer:
The correct option is C, a clam shell have a good possibility of being preserved because it has a hard body.
Step-by-step explanation:
In evolutionary studies, preservation are made in the form of fossils or remnants.
For an organism to be preserved, it must not decay early and it should be hard enough. When an organism is buried quickly then it will take more time to decay and hence will have more chances to be preserved.
As the clam shells are hard so this quality makes them ideal enough to be preserved.