The region very close to the point O will be dark
Hyperbolic bright and dark bands with foci symmetrically placed about O in the x-direction.
Semi circular bright and dark bands centered at point O
Straight bright and dark bands parallel to the x-axis
Fringes will be semi circular from YDSE theory.dλ=1000+12At O,Δx=1000λ+λ2Hence it will be dark at O.Answer is A and B.