All can be good choices. If law school is the plan, A&M in-state will be significantly help save a lot of money toward law school. If money is no object, all 3 are great so pick the one you like best or best fit.
If no law school, all 3 would probably have similar caliber outcomes for business unless you are going into I-banking. If I-banking is a potential goal, SMU and Kelley may have some benefit…but could cost twice as much or more.
If you plan to stay in Texas, A&M and SMU may have some advantage though a degree from any of the 3 should help you do well anywhere in the US.