Huge thanks to everyone chiming in. It’s good to hear that even at top colleges AO’s won’t dismiss an app automatically if it doesn’t have an MD checked. D will definitely take BC next year, but first semester should be easier for her, will give her more time for all the apps, etc. I am not stressing out over this, was just curious. Got two very good pieces of advice from this conversation - take AP Science instead of AP Stats next year and (via private email) check out Econ major pre-reqs at various schools - some require only Calculus BC, some require more advanced math, so an Econ minor instead of major might be a better option. Again, thanks everyone!