Prism dispersion: deviation increases with light frequency

Steps:

• Refractive index n of prism glass is higher for higher-frequency light (blue > red).
• Deviation angle d depends on n via formula d ≈ (n - 1)A, where A is prism angle.
• Since n increases with frequency, d increases with frequency.
• Blue light (higher frequency) deviates more than red light.

Why D is correct:

• D shows d increasing with frequency, consistent with n(ω) increasing for dispersive media.

Why the others are wrong:

• A: Incorrectly shows d decreasing with frequency, opposite to dispersion.
• B: Shows constant d, ignoring frequency dependence of n.
• C: Shows d peaking then dropping, not matching monotonic increase in prisms.

Final answer: D