Gravitational field intensity at the centre of the semi circle formed by a thin wire `AB` of mass `m` and length `L` is
A. `(Gm)/(l^(2))"along+xaxis"`
B. `(Gm)/(pil^(2))"along+xaxis"`
C. `(2piGm)/(l^(2))"along+xaxis"`
D. `(2piGm)/(l^(2))"along+xaxis"`
