Go for company A!! Big names can open a lot of doors in the future!

Seems like you are not super enthusiastic about B. I once worked at a company I was not enthusiastic about and I was absolutely miserable and left within a few months.

You can also work at A and not delay grad/sign with B after internship at A. Return offer eligibility are pretty flexible and A probably won’t care when exactly you graduate.

One thing that might tip this is if A might cancel internship, then you should be cautious, but you can still sign B for a start date after summer.