On the x-y coordinate plane there is a parabola, y=x(4-x). Which of the following points is in the region that is enclosed by this parabola and the x-axis?
I. (1, 4) II. (2, 3) III. (4, 1)
Select the correct option:
A) I only B) II only C) III only D) I and II E) I, II, and III
Since co-efficient of x^2 is negative, the parabola will be downward facing. So the parabola and the x axis will enclose some points where the y-values of the parabola are positive.   When x = 1, y = 3 lies on the parabola, so (1, 4) will not be enclosed by the parabola and x axis.   When x = 2, y = 4 lies on the parabola, so (2, 3) will lie below it and this point will be enclosed by the parabola and x axis.   When x = 4, y = 0 lies on the parabola, so (4, 1) will not be enclosed by the parabola and x axis.   The answer is II only.
<result>B</result>
On the x-y coordinate plane there is a parabola, y=x(4-x). Which of the following points is in the region that is enclosed by this parabola and the x-axis?
I. (1, 4) II. (2, 3) III. (4, 1)