A column of length ‘L’is fixed at bottom end and hinged at the other end. This column is restrained from lateral displacement at $${\frac{1}{3}^{rd}} $$height. The buckling load is given by

A

$$\frac {9\pi^2 EI}{(4L^2)}$$

B

$$ \frac {4\pi^2 EI}{L^2} $$

C

$$\frac {4\pi^2 EI}{(9L^2)}$$

D

$$\frac {\pi^2 EI}{L^2} $$