Which of the Following Would Likely Fossilize Under Normal Environmental

Which of the following would likely fossilize under normal environmental conditions?

A) An elephant that died near a waterhole that dried up.
B) A bird that died and fell into the forest litter.
C) A slug that died in leaf litter.
D) A soft shelled crab that dies in an estuary.
E) Both a bird and slug that die and fall in leaf litter.