I think its C.
I hope this helps and please do correct me if im wrong.
The answer is false.
The variability in marine salinity between habitats does impact the fish living there.
I hope this helps.
Think of it this way:
DNA inside cells store all the genetic information on a person's looks, eye colour, hair colour etc. It makes them unique. The analogy of being like books in a library basically suggests that in a library there is so much information and every book is different with different knowledge... That's basically what DNA is; millions of different information things.
I think that’s right thanks for the point god bless