一道GMAT数学题求解.
If y≠3 and 3x/y is a prime integer greater than 2,which of the following must be true?
1.x=y
2.y=1
3.x and y are prime integers.
A None
B 1 only
C 2 only
D 3 only
E 1 and 3
答案给出的是A，我觉得选B，请问条件1有什么问题？