Cory writes the polynomial x7 + 3x5 + 3x + 1. Melissa writes the polynomial x7 + 5x + 10. Is there a difference between the degree of the sum and the degree of the difference of the polynomials?

Adding their polynomials together or subtracting one polynomial from the other both result in a polynomial with degree 7.
Adding their polynomials together or subtracting one polynomial from the other both result in a polynomial with degree 5.
Adding their polynomials together results in a polynomial with degree 14, but subtracting one polynomial from the other results in a polynomial with degree 5.
Adding their polynomials together results in a polynomial with degree 7, but subtracting one polynomial from the other results in a polynomial with degree 5.