ANS:C - Crushing load or columns is less than the buckling load.

The wrong statement is: "For a helical spring, deflection is proportional to D^3 (D = mean coil diameter) or d^4 (d = wire diameter)." The correct relationship for the deflection of a helical spring is typically expressed as: Deflection ∝ (Force applied) / (Spring rate) While the mean coil diameter (D) and wire diameter (d) do influence the behavior of a helical spring, the relationship with deflection is not directly proportional to D^3 or d^4. Instead, these parameters affect other properties such as the number of active coils, spring rate, and stress distribution. The statement provided in option 2 is incorrect because it oversimplifies the relationship between deflection and spring geometry.