A beam of light is incident through the holes on side A and emerges out of the holes on the other fa......

A beam of light is incident through the holes on side A and emerges out of the holes on the other face of the box as shown in the figure. Which of the following could be inside the box? 

Since, in the figure all the parallel rays converge at a point. So, inside the box there must be a convex lens.

By: santosh