What crop allowed the early english colony of virginia to become profitable and survive?

Ineed answers 5 and 6 on my social studies homework reply to this question i posted

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 these is an edge city? boston, ma chicago, il irvine, ca detroit, mi