A Light Triangular Plate OAB Is in a Horizontal Plane

Multiple Choice

A light triangular plate OAB is in a horizontal plane. Three forces, F₁ = 6.0 N, F₂ = 9.0 N, and
F₃ = 7.0 N, act on the plate, which is pivoted about a vertical axes through point O. In the figure,
₂ is perpendicular to OB. Consider the counterclockwise sense as positive. The sum of the torques about the vertical axis through point O, acting on the plate due to forces F₁, F₂, and F₃, is closest to

A) 4.1 N ∙ m
B) 5.4 N ∙ m
C) -4.1 N ∙ m
D) -5.4 N ∙ m
E) zero