Which of the following diagrams correctly shows the dispersion of white light by a prism?

Two thin prisms of flint glass, with refracting angles of $6^o$ and $8^o$ respectively, possess dispersive powers in the ratio

$A$ ray of monochromatic light is passing through an equilateral prism $(ABC)$ as shown in the figure. The refracted ray $(QR)$ is parallel to its base $(BC)$ and the angle of incidence $(i)$ is $50^\circ$. Then the angle of deviation $(\delta)$ is: (in $^\circ$)

For a prism with a refractive index of $1.5$,what is the prism angle $A$ if the angle of minimum deviation is equal to the prism angle (in $^\circ$)? (Given: $\cos 41^\circ = 0.75$)

The diagram shows five isosceles right-angled prisms. $A$ light ray incident at $90^{\circ}$ at the first face emerges at the same angle with the normal from the last face. Which of the following relations will hold regarding the refractive indices?

Derive ${D_m} = A({n_{21}} - 1)$ for a thin prism.