You weren't caught napping if you picked B. "Lit," the French word for "bed," produced "litiere," which could refer to any sleeping place, but was usually applied to either a curtained portable couch or to straw spread on the ground as a sleeping place for animals. When borrowed into English, the "bedding for animals" sense was extended to the offspring of an animal that gives birth to a number of young all at once. By the 18th century, the meaning of "litter" was extended further to include any odds and ends of rubbish lying around. The absorbent material often called "kitty litter" is a more recent development.