CSULB vs UCSD

I was accepted CSULB back in feb. and I liked the campus and everything I recently accepted their offer and paid for the housing deposit and SOAR. I just heard back from UCSD and got accepted. I am from San Diego so i would be staying my my home town. Can i withdraw my acceptance from long beach still ?

I am a biology major i feel like UCSD is the better choice since they have medical school and i would like to apply to ucsd medical school in the future. CSULB has a good program and a minor in forensic which i would like to get if i went there.
I am a bit torn in which is the better option.