Help me in solving PYSTRMCQ3 problem

My issue

how is last option correct I just couldn’t understand that

Learning course: Strings using Python
Problem Link: CodeChef: Practical coding for everyone

@priyanshu7173
Initially A is a server .
1st B score , B becomes server.
2nd B score, B gain one point,
3rd A score, A becomes server.
4th A score, A gain one point.
so they end up having 1,1 score.