If $d$is the distance between slits and $\theta$is the angle between $0\mathrm{th}$ order maxima and $n\mathrm{th}$order maxima, then for diffraction pattern $d\sin \theta =n\lambda$

Now, if the source is replaced by another source of shorter wavelength, then $\sin \theta$becomes smaller. Therefore, the angle of diffraction for all orders reduces due to which the pattern shrinks and images move towards the normal, not diffracted beam.

Hence, the images C,B and A will shift towards O