I get the same questions all the time. What people don't realize is that AA culture is very diverse and that skin colors and hair textures can run the gamut. All of us are mixed if we look back far enough.
I usually just say I'm a mixture of my parents- both of whom have hair like mine. I leave it very ambiguous. The way I answer, they don't tend to probe too much.
Don't let them bother you. Take care of your hair, keep it healthy, and enjoy it!
By the way, your hair is lovely. The picture with the puff really reminds me of my hair before it grew to the point that the puff was less curly.