Answer
B.
Work Step by Step
A. is parasitism, C. and D. are mutualisms, not commensalisms. The anemone gets no benefit from the clownfish, making that a commensalism.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.