Correct option is D

As per IS 456: 2000
The recommended value of the effective length of the column effectively held in position and restrained in directions (or against rotation) at both ends is 0.65 times the length of the column.
The effective length of a given column (Leff) = 0.65 × L
The effective length of a given column (Leff) = 0.65 × 5 = 3.35 m
The effective length of column (Leff) = 3.25 m