Based on this pedigree, it is most reasonable to conclude that Becker muscular dystrophy is which of the following?

It is a sex-linked recessive trait since only men seem to be affected

the father in the first generation probably had the recessive colorblind trait in his x chromosome. if he and his wife both had the colorblind trait, even if she had 1 recessive and 1 dominant, then that trait would be passed on to their kids.

(since you didn't attach the family tree this is just an assumption)