Answer: Option (b) is the correct.
Explanation:
It is known that energy is directly proportional to frequency.
Mathematically, 
or, E =
............ (1)
where, E = energy
h = Plank's constant
= frequency
This relation shows that higher is the energy then more will be the frequency of electrmagnetic radiation.
Also,
......... (2)
where, c = speed of light
= wavelength
Therefore, substituting value of
from equation (2) into equation (1) as follows.
E =
E =
This relation shows that higher is the energy then lower will be the wavelength.
Thus, we can conclude that as the energy of a photon increases, its frequency decreases, is incorrect statement.