Which is a complete list of factors of each term in the expression 16 a + 18 a b?
16a: 1, 2, 4, 8, 16
18ab: 1, 2, 3, 6, 9, 18
16a: 1, 2, 4, 8, 16, a
18ab: 1, 2, 3, 6, 9, 18, b
16a: 2, 4, 8, a
18ab: 2, 3, 6, 9, a, b
16a: 1, 2, 4, 8, 16, a
18ab: 1, 2, 3, 6, 9, 18, a, b