What is everyone's opinion when it comes to the question of one's ethnicity...?

on applications in regards to it only listing Hispanic Latino/Not Hispanic Latino. I sorta feel offended. I am a Latina, raised in Houston, but born in Mexico. I am actively seeking employment and I have noticed this on EVERY application, whether online or one that I am actually filling out on paper. I wonder if they are just using this as an excuse to not hire me. I actually find myself second guessing if I want to answer it or opt out. I am not ashamed of who I am but I ask why are they targeting only hispanics/latinos? Do they assume that we are all here illegally? Am I just being too sensitive? What are your thoughts.