Gatsby has tan skin and short hair, but otherwise, most of Gatsby's characterization comes through his dialogue and actions—Nick doesn't linger on his physical appearance the way he does with other characters (especially Tom and Myrtle).
Some synonyms of the word superfluous include: nonessentional, unneeded, unused, etc.
So, in this question I believe the best definition of the world superfluous would be C. Unneeded.
Hope this helped!
I don't understand what your question is.
