The graph of function g is a parabola with the vertex located at (5, 9). The parabola also passes through the point (3, 1). Which of the following is an equation in vertex form for this function?
a) g(x) = 2(x - 5)² + 9
b) g(x) = 2(x - 5)² - 9
c) g(x) = 2(x - 5)² - 9
d) g(x) = "2(x + 5)² + 9