Prism separates white light via dispersion and refraction Steps:

• White light refracts upon entering the prism at point X, bending due to speed change in glass.
• Dispersion occurs at X as violet bends most and red least, separating colors by wavelength-dependent refractive index.
• Light refracts again when exiting the prism, further spreading the spectrum.
• Red light, with minimal deviation, reaches point Z on the screen.

Why C is correct:

• Snell's law shows refraction bends light (n sin i = n' sin r), while dispersion arises from varying n by wavelength; red (longest λ) deviates least per prism deviation formula δ = (n-1)A.

Why the others are wrong:

• A: Ignores refraction, essential for bending and enabling dispersion.
• B: Blue light deviates most, not reaching Z (red's position).
• D: Omits dispersion, but spectrum at Z requires color separation.

Final answer: C