Darwin's next insight was to compare process in nature to artificial selection. By doing so, he developed a scientific hypothesis to explain how evolution occurs. This is where Darwin made his contribution and his strongest break with the past.

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)

answer: the answer is b