The correct answer is b. Mestizo.
Mixtec, Maya and Nahua(tl) are the names of the indigenous people of Mexico (one of many): Mixtecs and Nahuas (the language is called Nahuatl) live dispersed throughout central and southern Mexico, and the Mayas live in the Yucatan Peninsula and in southern parts of Mexico and in Guatemala.
Mestizo means "mixed" in Spanish.
