The refractive index of water in a biology laboratory tank veries as $1.33+0.002 / \lambda^{2}$, where $\lambda$ is the wavelength of light. Small pieces of organic matter of different colours are seen at the bottom of the tank using a travelling microscope. Then the image of the orgainc matter appears

• A

  deeper for the violet pieces than the green ones.
• Correct answer
  B

  shallower for the blue pieces than the orange ones.
• C

  at the same depth for both the blue and orange pieces.
• D

  deeper for the green pieces than the red ones.

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