If x = 2015, y = 2014 and z = 2013, then value of x2 + y2 + z2 xy yz zx is

If x = 2015, y = 2014 and z = 2013, then value of x2 + y2 + z2 xy

1.	If x = 2015, y = 2014 and z = 2013, then value of x2 + y2 + z2 xy yz zx is
A.	3
B.	4
C.	6
D.	2
Answer» B. 4