Cual de las fracciones es diferente a las demás y porque

Why was the taiping rebellion significant

Why would the saudi’s oil industry need a large investment in human capital

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.