SDSU is very hard to get into. Not sure about biology specifically, but if you check out the rankings on US & World report, sdsu has a lot of top programs (I know chemistry and nursing are up there). If medical school is the plan, you should go for the college that will save you the most money. Look into scholarships. See which school of the three will give you the most money. If you are in-state then you will be saving a lot. Trust me. Choosing a school where I could save the most was the best decision I ever made. I was looking at uc davis, saint mary's and USC but I went with sdsu because of my scholarship. I currently work with people who are drowning in debt because they went to USC, Amherst, and UCSD I while I have zero student debt. Another piece of advice I would give you is to pick a school based off liking the specific school. A lot of people change their majors, there's no shame in that, but you don't want to get stuck at a school you don't like. Congrats on getting into great schools, best of luck!