Leaf-cutter ants harvest plant leaves and bring them back to their nests. There, in the warm, moist environments of their underground nests, they grow fungi (Leucoagaricus) that they then eat. These ants also host bacteria on their exoskeleton. Another fungus, Escovopsis, kills Leucoagaricus when the ants are removed from the nest. Knowing that the bacteria on the ants are in the same phylogenetic group of other bacteria that produce antibiotics, which of the following research hypotheses is most likely correct?
a) The bacteria on the exoskeleton produce chemicals that kill Escovopsis.
b) The bacteria on the exoskeleton provide nutrition to the ants.
c) The bacteria on the exoskeleton produce chemicals that kill Leucoagaricus.
d) The bacteria on the exoskeleton cause disease in the ants.