Given that $5x=3y=z$ where $x, y, z$ are integers, each choice given below must be integer except?
A) $z/15 \quad\quad $ B) $z/5 \quad\quad$ C) $z/3 \quad\quad\\ $ D) $z/xy \quad\quad\\$ E) $x/3$
(Ans=D)
How would I solve this problem any suggestions ?