A circular plate 100 mm. diameter is welded to another plate by means of 6 mm. size fillet weld. If the permissible shear stress in the weld is 100 N/mm^ then the greatest twisting moment that can be resisted by the weld is
A4.242 π kNm
B3 π kNm
C2.121 π kNm
D0.6 π kNm