Pick out the wrong statement.

A. The equivalent stiffness of two springs (of equal stiffness 'S') in series is S/2 while in parallel is 2S

B. For a helical spring, deflection is proportional to D3 (D = mean coil diameter) or d4 (d = wire diameter)

C. Crushing load or columns is less than the buckling load

D. Modulus of resilience is proportional to (stress at elastic limit)2

Please do not use chat terms. Example: avoid using "grt" instead of "great".