What was most significant challenge that miguel trujillo had to overcome to vote ?

Indians could still not vote in New Mexico and Arizona as of 1948. The denial of the right to vote was in the constitution of the State of New Mexico. It stated that Indians living on reservations could not vote in state and federal elections. The Bureau of Indian Affairs had started to push to change such laws before the war started, but had gotten sidetracked by the war.    (Trujillo v. Garley)

The answer is option b and c.