If a and b are unique prime integers, which of the following must be odd? Choose the correct option:
A) a−b
B) 2a+2b
C) 2a−2b
D) 2a / 2b
E) ab^2
Any number multiplied by 2 has to be an even number. hence   a−bnswer a−b
<result>A</result>
If a and b are unique prime integers, which of the following must be odd?