CSS with computer science as an optional
 

Hi every one .
I wanna ask about the [B]PAS group's allocation[/B] .How many chances I have to allocate in a PAS group after clearing exam with computer science as an optional subject. Its my aim to allocate in a PAS group But I have seen no one who opt computer science and got allocate in PAS group. I have seen some people with computer science background but instead of opting their core subject mostly goes for a political science or IR. why people do that ?I am hoping for the honest reviews .
Thanks