$A$ $124 \ W$ bulb converts only $15 \ \%$ of the energy supplied to it into visible light of wavelength $640 \ \text{nm}$. How many photons are emitted by the light bulb in one second?

  • A
    $4 \times 10^{19}$
  • B
    $6 \times 10^{19}$
  • C
    $8 \times 10^{18}$
  • D
    $3 \times 10^{19}$

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