Long and short spans of a two way slab are ly and lxand load on the slab acting on strips parallel to lx and ly be wx and wy respectively. According to Rankine Grashoff theory

A

$$ W_x / W_y = l_y / l_x $$ 

B

 $$ W_x / W_y = ( l_y / l_x )^2 $$ 

C

$$ W_x / W_y = (l_y / l_x )^3 $$ 

D

$$ W_x / W_y = (l_y / l_x )^4 $$