The vertex of the graph of a quadratic function is (2, –1) and the y-intercept is (0, 7). Which of the following is the equation of the function? 

A.

y = 2x2 – 8x + 7

B.

y = 2x2 + 8x + 7

C.

y = 2x2 + 8x – 7

D.

y = 2x2 – 7x + 8