If $$A = \begin{bmatrix}1 & -1 \\2 & -1 \end{bmatrix}, B = \begin{bmatrix}x & 1 \\y & -1 \end{bmatrix}$$ and $$(A + B)^2 = A^2 + B^2$$, then (x, y) =

A

(-2, -2)

B

(1, 4)

C

(-1, 4)

D

(1, -4)