For any x value in the interval from seven to 12, the value of g of x is positive. That is true, so I like this one. Let me see these other ones. F is positive over the closed interval from zero to seven, and it is non-negative over seven to 12. I like this one as well. And actually, the reason why I would rule out this first one, this first one has nothing to do with the derivative, and so it's not a calculus-based justification, so I would rule that one out. This one is good.