If a and b are odd integers, which of the following must be an even integer?	Choose the correct choice from the following choices.
A) a(b – 2)
B) ab + 4
C) (a + 2)(b – 4)
D) 3a + 5b
E) a(a + 6)
3a+5b==0dd*odd + odd*odd =odd+odd = even.   ANSWER:3a + 5b
<result>D</result>
If a and b are odd integers, which of the following must be an even integer?