A whistle producing sound waves of frequencies 9500 Hz and above is approaching a stationary person with speed $\nu \; ms^{-1}$. The velocity of sound in air is $300 \; ms^{-1}$. If the person can hear frequencies upto a maximum of 10,000 Hz, the maximum value of $\nu$ upto which he can hear the whistle is :

Question

( A ) $15\; ms^{-1}$
( B ) $30\; ms^{-1}$
( C ) $15/ \sqrt{2}\; ms^{-1}$
( D ) $15 \sqrt{2}\; ms^{-1}$