The expression (x – y)(x2 + xy + y2) + (x + y)(x2 – xy + y2) – (x + y) (x2 – y2) is equal to

The expression (x – y)(x2 + xy + y2) + (x + y)(x2 – xy + y2) �

1.	The expression (x – y)(x2 + xy + y2) + (x + y)(x2 – xy + y2) – (x + y) (x2 – y2) is equal to
A.	x3 – y3 + xy(x + y)
B.	y3 – x3 + xy(y + x)
C.	x3 + y3 + xy(y – x)
D.	x3 + y3 + xy(x – y)
Answer» D. x3 + y3 + xy(x – y)