Answer: C. inner organs
Step-by-step explanation:
Entrails usually refer to exposed inner organs and intestines of an animal and in this case is the best match for the word.
Cats are a natural predator for moles but have been known to discard certain parts of the mole's insides such as the bladder. Mrs. Whitney's cat most probably kept killing moles and then discarding the inner organs it did not eat on her front step.