Which one is the sex linked trait

Given below is a pedigree chart showing the inheritance of a certain sex- linked trait in humans.

The trait traced in the above pedigree chart is

Which of these is not a Mendelian disorder?

Given below is a highly simplified representation of the human sex chromosomes from a karyotype. The gene $'a'$ and $'b'$ could be of

Person whose father is colourblind marries a lady whose mother is daughter of a colourblind man. Their children will be

Which of the following is a sex-linked character