honestly. you should have just looked at her and yelled
"BECAUSE YOU'RE BLACK!!!!!!!!!!!!!"

because you KNOW that's probably the answer that she's looking for.

had that happen to me at work once. we had a guy "sampling" (handing out pieces of cookie for customers to sample) and this black woman in the corner called me over (while I'm wiping down tables) and asks me why the guy sampling cookies didn't give one to her.
and it's not like he gave cookies to everyone BUT her. he only hit the booths, not the individual tables.

and I HONESTLY just wanted to be like. YEP WOMAN, IT'S BECAUSE YOU'RE BLACK.