Answer:
A. The coefficients of the sum are whole numbers and the sum is a polynomial.
Step-by-step explanation:
The approach to demonstrate the closure property for the sum consists in defining what a polynomial is and demonstrate that the sum of two polynomials with integer coefficients is equal to a polynomial with integer coefficients. We proceed to show the proof below:
1) ,
Given
2) Definition of addition
3) Definition of substraction/Associative and Commutative properties
4) Distributive property/Definition of substraction
5) Definition of addition/Result
Hence, the coefficients of the sum are whole numbers and the sum is a polynomial. The correct answer is A.