The correct option is D 3.75 eV
According to Planck's Quantum theory,
E = hv = hcλ
where h = Planck's constant
v is the frequency of the photon
λ = wavelength of the photon = 331 nm = 331×10−9 m
So, E = 6.626×10−34×3×108331×10−9
E = 6.0×10−19 J
We know, 1 eV = 1.6×10−19 J
∴ E = 6.0×10−191.6×10−19 = 3.75 eV