If x and y are unique prime integers, which of the following must be even?	Choose the correct choice from the following answers
A) x−y  B) x−2y  C) 2x−2y  D) 2x−y  E) xy^2
Any number multiplied by 2 has to be an even number   Answer 2x−2y
<result>C</result>
If x and y are unique prime integers, which of the following must be even?