A whistle producing sound waves of frequencies $9500\text{Hz}$ and above is approaching a stationary person with speed $v\text{m/s}$. The velocity of sound in air is $300\text{m/s}$. If the person can hear frequencies up to a maximum of $10000\text{Hz}$, the maximum value of $v$ up to which he can hear the whistle is:

1. A
   $30\text{m/s}$
2. B
   $15\sqrt{2}\text{m/s}$
3. C
   $15/\sqrt{2}\text{m/s}$
4. D
   $15\text{m/s}$