Question

a relationship between two organisms in which both organisms benefit. commensalism parasitism competition mutualism

Explanation:

In biology, mutualism is a symbiotic relationship where both organisms involved benefit from the interaction. Commensalism is when one organism benefits and the other is neither helped nor harmed. Parasitism is where one organism (the parasite) benefits at the expense of the other (the host). Competition is a relationship where organisms vie for the same resources.

Answer:

Mutualism