If P kg /m$$^2$$ is the upward pressure on the slab of a plain concrete footing whose projection on either side of the wall is a cm. the depth of foundation D is given by
A] $$D = 0.00775 a\sqrt{P}$$
B] $$D = 0.0775 a\sqrt{P}$$
C] $$D = 0.775 P\sqrt{a}$$

A

A only

B

B only

C

C only

D

None of these