Simplify the following expression.
2x+3x³-5x² + x² +7x+1+7x5-3x³-4

A. 9x - 4x +7x+5
B. 5x5 +5x² +7x-3
C. 9x5 +6x +7x+3
D. 9x - 4x² +7x-3