Which plot would be the most effective disguise for an artist to speak out against pet overpopulation?

a. short story: a young hippo tells his story of growing so big that no home could hold him, so he sets out on his own to survive.
b. stage play: a pack of rabbits find themselves in need of a new leader, so they devise a plan to set up a government to maintain order in their rabbit world.
c. movie: a documentary traces the background of a dog sold at the local pet store all the way back to its birth at a puppy breeding farm.
d. song: a kitten sings about his adoption from a charity organization into a new family.