the question is asking what would be the best evidence arguing that the migrants were intruders. So Most of the migrants headed for the cities of California explains that the migrants are intruders because they aren't from California. Also it can't be the all the other choices because they are not specific on where the migrants are heading.
yes because if i have 100 dollars and i want to buy a Lamborghini i can't but i can buy food and all so we need to work and fulfill our great expectations