Which of the following is equivalent to (x+1)5−(x−1)5(x + 1)^5 - (x - 1)^5(x+1)5−(x−1)5?
2(5x4+10x2+1)2(5x^4 + 10x^2 + 1)2(5x4+10x2+1)
10x4+20x2+210x^4 + 20x^2 + 210x4+20x2+2
2(x5+1)2(x^5 + 1)2(x5+1)
10x4−10x2+210x^4 - 10x^2 + 210x4−10x2+2