If two forces are in equilibrium, then the forces must (i) Be equal in magnitude (ii) Be opposite in sense (iii) Act along the same line A. (i) and (ii) B. (i) and (iii) C. Only (i) D. All (i), (ii) and (iii)

The correct answer is: D. All (i), (ii) and (iii)

Two forces are in equilibrium if they cancel each other out. This means that the forces must be equal in magnitude, opposite in sense, and act along the same line.

If the forces are not equal in magnitude, then the net force will be non-zero and the object will accelerate.

If the forces are not opposite in sense, then the net force will have a non-zero component along the line of action of the forces, and the object will accelerate in that direction.

If the forces do not act along the same line, then the net force will have a non-zero component perpendicular to the line of action of the forces, and the object will rotate.

Therefore, for two forces to be in equilibrium, they must be equal in magnitude, opposite in sense, and act along the same line.