【单选题】

If x，Y and z are consecutive integers and x＜y＜z，which of the following must be true

Ⅰxyz is even．
Ⅱx+y+z is even．
Ⅲ (x+y)(y+z)is odD、
A、None
B、Ⅰonly
C、Ⅱ only D、Ⅰ and Ⅲ only
E、Ⅰ，Ⅱ，and Ⅲ