Question

look at the word in bold in paragraph 4.
hungry and willing to clean the parasites off the fish. the fish then changes its color from light to dark. this color change provides a signal to the shrimp that the fish wants to be cleaned.
4 cleaner shrimp do a thorough job of cleaning each fish. they will clean a fish from head to tail, and they will even climb into a fishs mouth to clean it. however, large fish could be dangerous for these tiny shrimp, so the shrimp have to be picky about which fish they choose to clean. they will only dance and wave to a fish that does not appear threatening. also, they will wait until the fish darkens the color of its scales before starting the job. if a fish moves toward a shrimp but does not change color, the shrimp knows that instead of getting a meal, it is at risk of becoming one!
what is the meaning of thorough as used in the text?
complete easy quick exciting

Explanation:

To determine the meaning of "thorough" in the text, we analyze the context. The sentence says cleaner shrimp clean a fish from head to tail and even climb into its mouth. This shows they do a complete job, not an easy, quick, or exciting one. So "thorough" means complete here.

Answer:

A. complete