The intercept on the line $y=x$ by the circle $x^2 + y^2 -2x=0$ is AB. Equation of the circle on AB as a diameter is

Question

( A ) $x^2+y^2-x-y=0$
( B ) $x^2+y^2+x-y=0$
( C ) $x^2+y^2-x+y=0$
( D ) $x^2+y^2+x+y=0$