Which of the following is represented by ‘x’ in the diagram below.

The correct answer is: Lateral shift

The correct answer is c) Lateral shift.
When rays fall parallel and obliquely on the glass slab, the emergent beam shift away from the incident ray. The perpendicular distance between these two rays is called lateral shift.
Here emergent ray is the ray coming out of the glass glass and incident ray is the ray which strikes the surface.