The wavelength of light in air and some other medium are respectively \[{{\lambda }_{a}}\] and \[{{\lambda }_{m}}.\] The refractive index of medium is [RPMT 2003]

• A.            \[{{\lambda }_{a}}/{{\lambda }_{m}}\]                         
• B.            \[{{\lambda }_{m}}/{{\lambda }_{a}}\]
• C.            \[{{\lambda }_{a}}\times {{\lambda }_{m}}\]            
• D.            None of these