Where does the sunlit zone change to the twilight zone in the ocean?

The top zone is the euphotic or sunlit zone. This is the ocean zone that sunlight penetrates. Because this zone gets sunlight, photosynthesis can occur and plants can grow here. The sunlit zone goes down to about 660 feet.

i believe the correct answer from the choices listed above is the first option. the scientists need to look at the   validity of data, claims, hypotheses, and observations before  developing an argument. they base their arguments on facts that are present and they make sure they have proofs. 

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