Answer:
It could not continue to be divided by slavery.
Explanation:
We can rule out the middle choice because we know Lincoln advocated to end slavery, not legalize it. He is saying that the land could not survive if it continued to be divided over slavery, but he doesn’t say that it couldn’t ever stop being divided and reunite, as implied by the last option. The top one implies that the nation could not survive as it was unless there was change, which still left a possibility, and matches most closely to Lincoln’s quote.
