HELP QUICKLY PLEASE
Which statement shows how the product of (x + 3)^2 demonstrates the closure property of multiplication?

A. x^2 + 9 may or may not be a polynomial
B. x^2 + 6x + 9 may or may not be a polynomial
C. x^2 + 9 is a polynomial
D. x^2 + 6x + 9 is a polynomial