@GalibHasan
Quite the opposite, I'm afraid: the answer and the graph aren't matching at all.
As I've written two years ago (how time flies! I hadn't still graduated in Math then), A isn't a point, it's a parameter, or more precisely the lead coefficient of a parabola (y=Ax^2+Bx+C). They find the A such that the parabola passes through the origin, and the parabola in the picture definetely doesn't do that.
What's happening is either that they're doing another exercise altogether, or that (more likely, since there's a 4 here too) they're answering to a question like "how would you change the equation of this parabola, in order to make it pass through the origin?"