The correct option is B nR>nV
Photons are the packets of energy (or energy particle) which are emitted by a source of radiation.
Energy possessed by a photon is given by
E=hv=hcλ
If power of each photon is P, then energy given out in t second is equal to Pt. Let the number of photons be n, then
n=PtE=Pt(hc/λ)=Ptλhc
For red light, nR=PtλRhc
For violet light, nV=PtλVhc
∴nRnV=λRλV
As λR>λV
So, nR>nV