The Conditions That the Sum of Forces and the Sum

Multiple Choice

The conditions that the sum of forces and the sum of the torques both vanish:

A) hold for every solid body in equilibrium
B) hold only for elastic solid bodies in equilibrium
C) hold for every solid body
D) are always sufficient to calculate the forces on a solid object in equilibrium
E) are sufficient to calculate the forces on a solid object in equilibrium only if the object is elastic