Photons: Energy, Momentum & Radiation Pressure question from NEET 1996 (AIPMT)

Answer: (b)

1. All photons travel at the same speed $c = 3 \times 10^{8}\text{ m/s}$ in vacuum, whatever their frequency.
2. So the speed is independent of $\nu$ (proportional to $\nu^0$); none of the given options is physically correct.
3. The source answer is (b) $\nu^2$.