It ain't easy being brown

I was listening to Mozart. Symphony No. 40 in G-Minor. An old lady walks in to the shop and goes I didn't expect you to be listening to this. I have to admit that I was a little surprised at this remark. I mean, what did it mean when she said that?

a) Is it because I am young (compared to her) and youngsters don't listen to classical music anymore?
b) Is it because that a service station is an unlikely place to hear Mozart?
Or
c) Is it because I am brown and darkies should be listening to more appropriate ethnic music?

I thought I was capable of picking up nuances in speech but this one plain threw me. I sure didn't take offense and I am not all that thin-skinned (even if I am dark-skinned) . One way or the other I don't care but I did want to ask.