If the positive integer x is a multiple of 3 and the positive integer y is a multiple of 3, then xy must be a multiple of which of the following?
I. 3
II. 12
III. 9	Choose the correct choice from the following answers:
A) II only  B) I and III only  C) I and II only  D) II and III only  E) I, II, and III
x=3a   y=3b   xy=9ab   where a,b are integers   Hence , xy will always be divisible by 3,9 .   I and III only is the answer.
<result>B</result>
If the positive integer x is a multiple of 3 and the positive integer y is a multiple of 3, then xy must be a multiple of which of the following?
I. 3
II. 12
III. 9