This is discussed pretty frequently on the College & University forum. Mostly seems speculative, but try:
https://www.dcurbanmom.com/jforum/posts/list/1099822.page
https://www.dcurbanmom.com/jforum/posts/list/1039655.page
https://www.dcurbanmom.com/jforum/posts/list/1010582.page
My kid dropped Spanish after 5A, which was a real struggle due to a learning disability that the teacher wouldn't accommodate. (That inspired us to put a 504 plan in place, but alas, too late for Spanish.) DC is now taking ASL and enjoys it a lot. If that puts certain colleges out of reach, so be it. It wasn't worth DC being completely miserable.