Assuming Z= 3 and y= 2, what would be the result of : Z+=Y

Assuming Z= 3 and y= 2, what would be the result of : Z+=Y

A.
The value of Y is now 5

B.
The value of Y is now 3

C.
The value of Z is now 5

D.
The value of Z is now 2

E.
5