Which Square is different?

 

Okay the answer is below. When you are ready look at it. But to be honest, eventhough I am posting the answer I don’t know why they say this one is different? Can you tell me? Answer below:

.

.

.

.

.

.

.

.

.

Here is the answer

 

Eventhough I posted this, I don’t know if I see why ‘A’ is the one that is different from the others. Can anyone spot why and tell me? Answer in the comments below

Thanks

Ron