Which of the following describes a mutualistic relationship?

(A) A tapeworm feeds off its host's nutrients, causing the host to lose large amounts of weight.
(B) Certain plants grow on trees in order to gain access to sunlight, not affecting the tree.
(C) Remora fish eat parasites off sharks. The sharks stay free of parasites, and the remora fish are protected from predators.
(D) Meerkats sound alarm calls to warn other meerkats of predators.