I would just like to add some perspective as a student to this discussion. I have taken 4 AP science courses: Biology, Chemistry, Physics 1 and Physics C. I dropped Spanish for my senior year as I already had 5 other APs. During this past application season I have got into JHU, Cornell, and multiple BS/MD programs and am planning to attend a BS/MD program this fall. Basically what I’m trying to say is that foreign language is not a make or break for highly ranked schools or any of the schools your son is going to apply to.