The correct option is A a line whose equation is 2x−y−1=0
as property.
The locus of centre of circle cutting two given circle
orthogonally is the radial axis of two circles.
reqd equation is :-
S1−S2=0
∴ radial axis of x2+y2−1=0 and x2+y2−2x+y=0 is
⇒2x−y−1=0