The Answer is C, my good friend.
Hi,
You just have to change z^25 to z^24 or z^27.

To find the vertex of the parabola, we need to write it in a vertex form.
y=x² - 8x +12
1) complete the square
y=
x² - 8x +12
y =
x² -2*4x + 4² - 4² +12
y=
(x-4)² -16 +12
2) calculate and write a vertex
y=
(x-4)² -16 +12
y=
(x-4)² - 4
(x-4) ----- x- coordinate of the vertex x=4
y=(x-4)²
- 4 -------y- coordinate of the vertex y = - 4 Vertex is (4, -4).
Answer is (4, -4). No correct answer is given in choices.