When acolumn is fixed at both ends, corresponding Euler’s critical load is

A

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

B

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

C

$$\frac{3 \pi^2 EI}{L^2}$$

D

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