Aphids produce a sugary substance that ants love. Ants protect the aphids from predators and parasites. Is it commensalism, mutualism, parasitism, or predation?

The relationship between aphids and ants can be classified as mutualism. In mutualism, both species benefit from their interaction. The ants receive the sugary substance produced by the aphids, known as honeydew, as a food source, while the aphids receive protection from predators and parasites provided by the ants.