When two sound waves with a phase difference of $\mathrm{\pi }/2$, and each having amplitude A and frequency $\mathrm{\omega }$, are superimposed on each other, then the maximum amplitude and frequency of resultant wave is 

• A

  $\frac{\mathrm{A}}{\sqrt{2}}, \frac{\mathrm{\omega }}{2}$

• B

  $\frac{\mathrm{A}}{\sqrt{2}}, \mathrm{\omega }$

• C

  $\sqrt{2}\mathrm{A}, \frac{\mathrm{\omega }}{2}$

• D

  $\sqrt{2}\mathrm{A}, \mathrm{\omega }$