Polynomials are closed under the operation of addition. which statement best explains the meaning of closure of polynomials under the operation of addition? when any two polynomials are added, the result is always a polynomial with positive coefficients. when any two polynomials are added, the result is always a polynomial. when any two polynomials are added, the coefficients of like terms are always added. when any two polynomials are added, the result is always a monomial or a binomial.