Answer:
C. Determine whether the earthworms benefit from being with the plant
Explanation:
To answer the question, first, we need to keep clear the concept of mutualism as an interspecies interaction.
All organisms in nature interact with other organisms in different ways. Symbiotic interactions involve a relationship between two or more organisms of different species in which one or all of them turn to be beneficiated by that relationship. These species create permanent mutual dependence.
Symbiotic interactions include mutualism, commensalism, and parasitism.
Mutualism: The interaction is favorable for both species. Their fitness increases with these interactions, although they do not need this relationship to survive. The degree of benefits might vary among species or might be equal.
In the exposed example, the student already knows that the plant got beneficiated by the earthworm's presence. Now, to test mutualism, the student needs to figure out how the earthworms are beneficiated by the plant. What are the benefits of being with the plant?. If the student can not identify any advantage, then probably, the relationship between species is not mutualism but other.
