The remora fish attaches itself to sharks for transportation and access to food scraps. The shark is not harmed. What type of example is this?

Sorry this is late: You didn't put the answer options, but I was on this question, so the correct answer is commensalism. Don't forget to put the answer options, or no one will understand it. Good luck with the rest of your work!

A living or continuing longer than, or beyond the existence of, another person, thing, or event; an outliving.
2. Any habit, usage, or belief, remaining from ancient times, the origin of which is often unknown, or imperfectly known. The close bearing of the doctrine of survival on the study of manners and customs. (Tylor) Survival of the fittest.