A curved surface has the shape of one-quadrant of a 3 m long 2 m diameter cylinder with two edges parallel to the axis. The curved surface is immersed in a stationary liquid of unit weight 10 kN/m3 such that one straight edge is on the liquid surface and the other 1 m below the surface. The moment of vertical component of hydrostatic thrust on one side of the surface, about the axis of circular arc, is
(A) 7.854kNm (B) 10.0kNm
(C) 11.781kN/m (D) 15.708kNm