If a, b, and c are integers and ab^2/c is a positive even integer, which of the following must be true?
I. ab is even
II. ab > 0
III. c is even	Choose one
A) I only	B) II only	C) I and II	D) I and III	E) I, II, and III
ab2/c is positive which means a and C &gt;0 or a and c&lt;0 since b2 is positive   Case 1 - a=3 b=2 c=3 or c=6 where ab2 /2 would be even when c= 3 or c=6   lets see III option where C is even as per our assumption C can be even and odd, hence it is out.   lets see option II ab&gt;0 a and b can positive or negative hence sign of ab cannot be determined hence it is out   So options B,C,D,E are gone and ans is I only
<result>A</result>
If a, b, and c are integers and ab^2/c is a positive even integer, which of the following must be true?
I. ab is even
II. ab > 0
III. c is even