Two conducting circular loops of radii \[{{R}_{1}}\] and \[{{R}_{2}}\] are placed in the same plane with their centres coinciding. If \[{{R}_{1}}>>{{R}_{2}}\], the mutual inductance M between them will be directly proportional to [MP PMT 1994; MP PET 2001]

• A.            \[{{R}_{1}}/{{R}_{2}}\]     
• B.            \[{{R}_{2}}/{{R}_{1}}\]
• C.            \[R_{1}^{2}/{{R}_{2}}\]    
• D.            \[R_{2}^{2}/{{R}_{1}}\]