A protozoan and its resident bacteria invade the body of a worm. The bacteria release toxins and exoenzymes that immobilize and digest the worm, and the protozoan and bacteria absorb the nutrients produced. The relationship between the protozoan and the bacteria would best be described as:.
A) a nonsymbiotic relationship.
B) mutualism
C) parasitism
D) both commensalism and parasitism.
E) commensalism

A protozoan and its resident bacteria invade the body of a worm. The bacteria release toxins and exoenzymes that immobilize and digest the worm, and the protozoan and bacteria absorb the nutrients produced. The relationship between the protozoan and the bacteria would best be described as mutualism

Explanation:

Mutualism entails relationship between two or more organisms whereby both organisms gains. From the analogy above, it is clear that both the protozoan and bacteria benefit from the worm

explanation:

the fossil record extends back to a dog-like ancestor some 55 million years ago, which gave rise to the first horse-like species 55 to 42 million years ago in the genus eohippus.