Which is the best example of a secondary source document useful in the study of history?

Which of the following is an example of the pull factor known as economic migration? a. better educational opportunities pulling people towards a new country b. mexican laborers entering the us to work in agricultural jobs c. joining family members that are already in a new country d. crop failures driving people away from their country i am unsure on this question, i was thinking b? but i could be wrong.

Which of the following most accurately describes china today

Whose plan centered on keeping the federal budget balanced, instituting tax cuts, and developing public works projects?