(a) colleges factor in anything you tell them -- if your GPA was low bc you were somehow uniquely affected by COVID (you developed depression/anxiety/etc, a family member died/was severely affected, you didn't have good internet/a good computer, etc), they will DEFINITELY take that into account. they're trying to get a gauge at your academic competence -- if it was something you couldn't control, then it doesn't implicate your ability to do well academically.
(b) you should check out:
- stanford
- UMich (ross business school is really really good!!)
- Vanderbilt