For two way action, i.e. punching shear, the calculated shear stress, $$\tau_{y}$$ , should satisfy the following relation $$\tau_{y} \leq K_{s}\tau_{c} $$
where $$\tau_{c}$$ according to working stress method is expressed as

A

0.1 $$\sqrt{f_{ck}}$$

B

0.16 $$\sqrt{f_{ck}}$$

C

0.25 $$\sqrt{f_{ck}}$$

D

0.4 $$\sqrt{f_{ck}}$$