Which among the following values: 17, 20, 38, and 50, does not have primitive roots in the group G = <Zn*, >?

Which among the following values: 17, 20, 38, and 50, does not have pr

1.	Which among the following values: 17, 20, 38, and 50, does not have primitive roots in the group G = <Zn*, >?
A.	17
B.	20
C.	38
D.	50
Answer» C. 38