estuaries
Chesapeake Bay. The Chesapeake Bay is the largest estuary in the United States. It runs north-south from the mouth of the Susquehanna River to the Atlantic Ocean. It is one of the most productive estuaries in the world, with over 3,600 species of animals and plants.
I don't want to be rude or anything but this looks like it would be a math question
have you tried looking the word up in the Dictionary? if that doesnt help much, you can guesstimate the word by searching it in the thesaurus! it will give you synonyms of the word.
hope that helps!
I believe the answer is C. But I'm not 100% sure.