Consider telecommunication through optical fibres. Which of the following statements is not true?

• A

  Optical fibres can be of graded refractive index
• Correct answer
  B

  Optical fibres are subjective to electromagnetic interference from outside
• C

  Optical fibres have extremely low transmission loss
• D

  Optical fibres may have homogeneous core with a suitable cladding.

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