The correct answer is - B. Organisms with hard parts made of shell or bone are more likely to become fossilized.
If we go through the fossils we can easily notice that the fossils that have been found are by far dominated by bone and shell remains of animals, rather than animals without bone structure or plants.
The reason for this is that the organisms decompose very quickly, and it is the hard parts, the bones and the shells that remain as the last parts once an organism is dead. The soft tissue is almost impossible for preservation, even in perfect conditions for preservation of an average fossil. The hard parts, on the other hand, are able to remain as they are for millions of years, with only basic conditions for preservation, and the reason for that is the material from which they are made off.
This is the reason why when we go to natural museums we mostly see skeletons of died out animals, while the fossils of animals without any hard parts, or those of plants, are usually prints on rocks, being more of a picture, but not containing part of the real thing.