# Beams of light are incident through the holes A and B and emerge out of the box through the holes C and D respectively as shown in the Figure. Which of the following could be inside the box? (a) A rectangular glass slab (b) A convex lens (c) A concave lens (d) A prism

Answer: (a) A rectangular glass slab

A rectangular glass slab might be inside the box since lateral displacement occurs in parallel rays. The distance by which incident light has been shifted after bending through the glass slab is known as lateral displacement.