Which of the following shows that polynomials are closed under addition when two polynomials 4x2 − 8x − 7 and −5x + 16 are added?

4x2 − 13x + 9 may or may not be a polynomial

4x2 + 13x − 23 may or may not be a polynomial

4x2 − 13x + 9 will be a polynomial

4x2 + 13x − 23 will be a polynomial