Simplify the difference.
(-7x - 5x^4 + 5) - (7x^4 - 5 - 9x)
A. 2x^4 + 2x + 8.
B. -14x^4 + 10x + 10
C. 2x^4 + 2x + 10
D. 2x^4 + 2x + 10