$v _{\text {air }}=\sqrt{\frac{\gamma_{\text {air }} R T}{ M }}$ (option 'A' and 'B' are not true for sound of velocity in air)
$v_{\text {wzeter }}=\sqrt{\frac{\gamma_{\text {water }}}{\rho}}$ (option ' $C$ ' and ' $D$ ' are not true for sound of velocity in air as air has more weight than moist air for same density of molecules) All are wrong.