Answer
Choice C.
Work Step by Step
Torque is the lever arm multiplied by the component of the force perpendicular to the arm.
The force of 1000 N force has no lever arm and no torque because it acts at the pivot.
The force of 800 N has no component perpendicular to the lever arm and also exerts zero torque.
Of the three 500-N forces, choice C is totally perpendicular to the lever arm and is applied farthest from the pivot. It will be most effective at giving the board an angular acceleration.
