If A and B are square matrices of the same order then

If $A$ and $B$ are square matrices of the same order then $(A-B)^{2}=$ ?.

A. $A^{2}-2 A B+B^{2}$

B. $A^{2}-A B-B A+B^{2}$

C. $A^{2}-2 B A+B^{2}$

D. none of these