A source simultaneously emitting light at two wavelengths $400\mathrm{nm}$ and $800\mathrm{nm}$ is used in the Young's double slit experiment. If the intensity of light at the slit for each wavelength is $I_0,$ then the maximum intensity that can be observed at any point on the screen is

• A

  $I_0$
• B

  $2I_0$
• C

  $4I_0$
• Correct answer
  D

  $8I_0$

Hence, the correct answer is option: 'D'.