there are two squares ABCD and PQRS each having side length of 2a. P is the centre of the square ABCD. If the point P is fixed and the square PQRS can be moved freely about it, which of the following statements is appropriate ?

Question

https://drive.google.com/file/d/0B_UYTZVc4r4mU3AzZlREYlp6bFE/view?usp=sharing
( A ) The area of the shaded region decreases as the length BX increases
( B ) The area of the shaded region increases as the length BX increases
( C ) There will be no change in the area of the shaded region with the change in the length of BX
( D ) There will be a change in the area of the shaded portion but not like the one mentioned under (b) and (c) above