The correct answer is that this is not a true statement.
It was not true that the survival of the Pilgrims would have been impossible without John Rolfe showing them how to farm tobacco.
We are talking about different things. The Pilgrims established in the area of Massachusetts when they arrived at Cape Cod in 1620. They have nothing to do with John Rolfe, in the colony of Jamestown, Virginia, that was founded in 1607.