If (x1,y1)&(x2,y2) are the ends of diameter of a circle such that x1&x2 are the roots of the equation ax²+bx+c=0 and y1&y2 are the roots of the equation py²+qy+c=0 . Then the coordinates f the centre of the circle is:
(a) (b/2a,q/2p)
(b) (−b/2a,=q/2p)
(c) (b/a,q/p)
(d) None of these