The earth?s magnetic field at a given point is \[0.5\times {{10}^{-5}}Wb\text{-}{{m}^{-2}}\]. This field is to be annulled by magnetic induction at the center of a circular conducting loop of radius 5.0cm. The current required to be flown in the loop is nearly [AIIMS 2003]

• A.            0.2 A       
• B.            0.4A
• C.            4A 
• D.            40A