De Broglie’s hypothesis states that every moving particle has a wave-like nature. The wavelength \( \lambda \) of a photon is related to its energy \( E \) by the following equation:
\[
\lambda = \frac{h}{p}
\]
Where \( h \) is Planck's constant and \( p \) is the momentum. For a photon, the momentum can be related to its energy \( E \) by \( p = \frac{E}{c} \), where \( c \) is the speed of light.
For a photon, the wavelength is given by:
\[
\lambda = \frac{h}{E}
\]
Thus, the correct answer is \( \lambda = \frac{h}{E} \).