A binomial is a polynomial that consists of exactly two terms.
Let's evaluate the options:
A. 5 - This is a constant and does not have two terms. (Not a binomial)
B. 2a x 3b - This expression has only one product term (which can be simplified to 6ab). (Not a binomial)
C. 3x - 5x + 3 - This can be simplified to -2x + 3, which has two terms. (This is a binomial)
D. 4x + 2y - This has two distinct terms and is also a binomial.
Both options C and D qualify as binomials, but since C simplifies to a binomial form, the clear answer is:
D. 4x + 2y is a binomial.
If we only need to identify one binomial from the options, it would be:
D. 4x + 2y.
(Note: If you're specifically looking for a direct response and only considering provided options, both C and D are technically binomials).