The pair having similar geometry is  
(a) $PC{l}_3,N{H}_3$  (b) $BeC{l}_2,SnC{l}_2$        
(c)  $SiC{l}_4,CC{l}_4$ (d)  $Xe{F}_4,S{F}_4$

(a) $PC{l}_3,N{H}_3$  - both are pyramidal 
(b)  $BeC{l}_2$is linear while  $SnC{l}_2$is angular
(c) $SiC{l}_4,CC{l}_4$ - both are tetrahedral 
d) $Xe{F}_4$ is square planar while $S{F}_4$ has See saw geometry.