Based on the cladogram, which group of plants is most closely related to the ancestors of all plants?

It considered that all terrestrial plant species that exist today have evolved from Rhyniophyta (a type of spore plants, compiled by the most primitive forms of vascular). Now terrestrial plants presents by the Moss family, psilotaceae, lycopsids, class of the Horsetail, fern, gymnosperms and flowering plants.  Based on the cladogram, It assumed that the ancestors of all existing plants are algae, particularly green.

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)