Help me in solving CSTRMCQ3 problem

My issue

I have undersatnd the situation given but not about A,s hand and B’s hand given

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

The rule is when server scores a point he will get a point else if receiver scores a point the receiver becomes server and don’t gets any point.
Now lets take ex BBAA.
Initially A is server and B scores which will make B as server.
then B scores again and B is also server which means B will get one point.
then A scores and B is server which will make A as server .
then A scores again which means A will get a point becozz A is server this time.
so at the end A has 1 point and B has 1 point which is equal.
thus in similar way u can calculate for each option and u will get equal scores for option A,C,D .