If a circle passes through the point `(a, b)` and cuts the circle `x^2 +y^2=k^2` orthogonally, then the equation of the locus of its center is

Options

A. a)`2ax+2by-(a^2+b^2+k^2)=0`
B. b)2ax+2by-(a^2-b/62+k^2)=0`
C. c)`x^2+y^2-3ax-4by+(a^2+b^2-k^2)=0`
D. d)`x^2+y^2-2ax-3by+(a^2-b^2-k^2)=0`