Which segment shows the cyclist stopping for a drink of water?

The only way to properly answer your question is with the image, but without it, I can still give you a guess of what it will be. 

Generally, with these types of problems, the cyclist will begin riding at an increasingly fast pace, Then they will begin slowing down, so the line decreases. When he stops for water the line should remain constant. Meaning a straight horizontal line such as this

If you can include an image I can give you the exact answer you're looking for, however.