These are all excellent schools, but the environments are quite different. If possible, I would visit them to see which feels most like home.
Also, delve into their curricula to see which would be the best academic fit.
Finally, if there is a large COA discrepancy – although you say you can afford all four, if there are large discrepancies (say, more than $50k over four years), I would consider that as well. You or your folks can use that extra money for something else, like their retirement or (for you) a down payment on a house or grad school expenses.