Master Page Data hide problem

Hi Experts

I create two master page A and B in my document and one pages whose master page is B.

Now using master page option for B master page I apply A master page on B master page.

Now A master data is on B master page and also on page whose master is B.

But i want that master A data is not present on page whose master is B, only B master page data should present.

If i use show/hide property then it hide all master (A and B both master page data) from the page whose master is B.

How can i do it manually and using script ?

Thanks