Special Ed Law School....?

My 8-year-old son just asked me how many Special-Ed students are in my law school. I told him none. He asked, "Why not?" I said, "Because no one who is Special-Ed could ever get into law school." He looked shocked and said, "Well, that's just not fair. What if they want to be lawyers?" I said back to him, "Well, they just couldn't be a lawyer. It wouldn't be an option for them." He looked disappointed and just shrugged "Oh, ok." I didn't feel right telling him this. I felt like it went against every thing I've taught him about beating the odds and becoming whatever you want to be. How should I have responded? I didn't know what else to tell him.