Which of the following statements about closure is false?
a. polynomials are closed under addition. when you add polynomials, the result
will always be a polynomial.
b. polynomials are closed under subtraction. when you subtract polynomials, the result will always be a polynomial.
c. polynomials are closed under division. when you divide polynomials, the result will always be a polynomial.
d. polynomials are closed under multiplication. when you multiply polynomials, the result will always be a polynomial.