If x, y, and z are positive integers such that x is a factor of y and y is a factor of z, which of the following is NOT necessarily an integer?
Choose the most appropriate option.
A) (x + y)/z	B) (y + z)/x	C) yz/x	D) (2y + 3z)/x	E) (xy + z)/y
As per the question, let x = 2, y = 6, and z = 12. Plugging these into the answer choices, only (x + y)/z does not yield an integer.
<result>A</result>
If x, y, and z are positive integers such that x is a factor of y and y is a factor of z, which of the following is NOT necessarily an integer?