Of the following, which is an example of a mutualistic relationship? (A) the protozoan Trichonympha digesting wood in the gut of a termite (B) the sporozoan Plasmodium reproducing in human blood cells and liberating toxins into the human body (C) two species of Paramecium deriving food from a common laboratory culture (D) rabbits being eaten by foxes (E) humans inadvertently providing food for cockroaches unanswered