When two sound waves with a phase difference of \[\pi /2\], and each having amplitude A and frequency \[\omega \], are superimposed on each other, then the maximum amplitude and frequency of resultant wave is [MP PMT 1989]

• A.            \[\frac{A}{\sqrt{2}}:\frac{\omega }{2}\]                      
• B.            \[\frac{A}{\sqrt{2}}:\omega \]
• C.            \[\sqrt{2}\,A:\frac{\omega }{2}\]                                   
• D.            \[\sqrt{2}\,A:\omega \]