The graph of a quadratic function crosses the x-axis at x=1 and x=5, has its axis of symmetry at x=3, and passes through the point (3,2). Which of the following equations satisfies all these conditions?
a) y=21(x−1)(x−5)
b) y=(x−3)2+2
c) y=−21(x−1)(x−5)
d) y=(x−1)(x−5)