Wavelength of light used in an optical instrument are \[{{\lambda }_{1}}=4000\]Å and \[{{\lambda }_{2}}=5000\]Å, then ratio of their respective resolving power (corresponding to \[{{\lambda }_{1}}\]and \[{{\lambda }_{2}})\]is [AIEEE 2002]

• A.            16 : 25                                     
• B.            9 : 1
• C.            4 : 5                                          
• D.            5 : 4