The spring index is,
(A) Ratio of wire diameter to mean coil diameter
(B) Force per unit cross-sectional area of spring
(C) Ratio of mean coil diameter to wire diameter
(D) Force required to produce unit deflection
(A) Ratio of wire diameter to mean coil diameter
(B) Force per unit cross-sectional area of spring
(C) Ratio of mean coil diameter to wire diameter
(D) Force required to produce unit deflection