Concept:Mutualism is a close relationship in which both organisms benefit from each other.
Explanation:The hermit crab and sea anemone exhibit mutualism because each partner gains an advantage.
The sea anemone attaches to the shell of the hermit crab and receives transport and food particles.
The hermit crab receives protection from predators because the anemone has stinging cells.
Hydra and sea anemone are not known to form this kind of beneficial relationship.
The dodder plant and cocoa plant show parasitism, because dodder draws nutrients from the cocoa plant.
Mistletoe and kolanut also show parasitism, since mistletoe takes water and minerals from the host plant.
Only the pair in option B shares a true mutualistic association.
Answer:B. Hermit crab and Sea anemone