If z2 + 4y2 = 4zy, then z : y is :  Choose the correct choice from the following choices:
A) 2 : 1
B) 1 : 2
C) 1 : 1
D) 1 : 4
E) 1 : 5
as the coefficient of z is 1 and coefficient of y is 4   ANSWER:1 : 4
<result>D</result>
If z2 + 4y2 = 4zy, then z : y is :