They are all freshwater. So the closest would be c. an estuary since it has a free connection with the sea since the sea is not freshwater.
So C.
hope this helps!
4 i guess........................
Hello,
Here is your answer:
The proper answer to this question that it "can take more than <span>thousands of years for the process to be completed"!
If you need anymore help feel free to ask me!
Hope this helps!</span>
