I've looked us up ever since you posted it the only thing I can come up with is letter A because it talks a lot about Mountain chains that talks a lot about the ocean floor and the Hawaiian stuff so try a
So the mom has the genes of Ww because for the first kid not to get it she must have a recessive gene. The Father for sure has 2 recessive genes, ww, meaning the kid has a 50/50 chance. The kid could get Ww or ww.