A tuning fork is used to produce resonance in a glass tube. The length of the air column in this tube can be adjusted by a variable piston. At room temperature of $27^{\circ }\text{C}$ two successive resonances are produced at $20\text{cm}$ and $73\text{cm}$ of column length. If the frequency of the tuning fork is $320\text{Hz}$, the velocity of sound in air at $27^{\circ }\text{C}$ is:

1. A
   $350\text{m/s}$
2. B
   $339\text{m/s}$
3. C
   $330\text{m/s}$
4. D
   $300\text{m/s}$