A Small Marine Amphipod Has Recently Been Discovered That Carries

Multiple Choice

A small marine amphipod has recently been discovered that carries a bad-tasting organism on its back,which is contrary to its normal behavior.If a fish ingests the pair,it immediately spits them back out.If the amphipod is alone,however,it is readily eaten.There is no apparent benefit or harm in this relationship for the "backpack" organism.This is probably a case of

A) mutualism.
B) parasitism.
C) commensalism.
D) competitive exclusion.