When an invading insect threatens an ant colony' s territory or food sources, the ants will vigorously swarm over the invader, biting or stinging it. This defensive tactic can effectively deter even aggressive flying insects, such as wasps. Ants do not attack all insects within their territory, however. For example, riodinid caterpillars commonly live harmoniously among South American ants. These caterpillars, which are a favorite prey of wasps, produce secretions the ants consume as food. Which one of the following is most strongly supported by the information above? ['With the sole exception of riodinid caterpillars, South American ants will vigorously attack any organism other than ants that use riodinids as a source of food.', 'Among insect species that inhabit South America, wasps are the only kinds of organism other than ants that use riodinid caterpillars as a source of food.', 'Riodinid caterpillars in South America that live among ants are less likely to be attacked by wasps than those that do not live among ants.', 'The secretions produced by riodinid caterpillars are chemically identical to substances secreted by plants on which South American ants also feed.']