So let's see which of these choices are consistent with that. Julia made an additional $19,000 between months one and five. Choice A would be correct if you didn't see this three over here, because just the definite integral is the additional between months one and five, but that's not what this expression says. It says three plus this is equal to 19. If it said Julia made an additional $16,000, well then that would make sense, because you could subtract three from both sides and you'd get that result, but that's not what they're saying. Julia made an average of $19,000 per month. Well once again, that's also not right, because we already just said from the beginning, from time zero all the way until the fifth month, she made a total of $19,000, not the average per month is 19,000.