Water in the deep ocean in the surface layer.

Because this is a little confusing and I know the options, here y'all go.

Water in the deep ocean is water in the surface layer.

a. warmer than

b. less salty than

c. more dense than

I don't know the answer I'm just helping the people who might know.

Water in the deep ocean is more dense than water in the surface layer.

explanation:

what doin