The following pairs consist of a subset in the set of polynomials R[x] and a binary operation in which case is the subset closed for the given operation?(a) {p ∈ R[x] | βp = 2 }; addition of polynomials.(b) {p ∈ R[x] | βp = 2 }; composition (composite) of polynomials.(c) {p ∈ R[x] | βp <= 2 }; multiplying polynomials.(d) {p ∈ R[x] | βp <= 2 }; composition (composite) of polynomials.(e) {p ∈ R[x] | βp >= 2 }; multiplying polynomials.