A saprobe differs from a parasite in that _______.
A) a saprobe derive nutrients from dead plants and animals, but a parasite derives nutrients from living plants and animals B) a saprobe cannot infect a human, but a parasite is always infectious C) a saprobe does not harm a host that it lives on, whereas a parasite does harm a host D) a saprobe is a fungus, but a parasite can be any type of microbe