B. 25 mm , the rest are too big for it to be a dinner plate.
I think it's
250 * 1x = M
Step-by-step explanation:
The equation given is of the form

where (h, k) are the coordinates of the vertex. So in this case, the vertex is located at (4, 2). Since a is a negative number (a = -3), this means that the vertex is a maximum because the parabola opens downward.