A car moving towards a cliff emits sound of frequency ' $n$ '. If the difference in frequencies of the horn and its echo heard by the driver of the car is $10 \%$ of ' $n$ ', then the speed of the car is nearly (Speed of sound in air is $336 \mathrm{~ms}^{-1}$ )

• Correct answer
  A

  $16 \mathrm{~ms}^{-1}$
• B

  $18 \mathrm{~ms}^{-1}$
• C

  $30 \mathrm{~ms}^{-1}$
• D

  $33 \mathrm{~ms}^{-1}$

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