Correct option is DGiven:1−x41+x÷1+x2x×1x(x−1)\frac{1 - x^4}{1 + x} \div \frac{1 + x^2}{x} \times \frac{1}{x(x - 1)}1+x1−x4÷x1+x2×x(x−1)1Concept Used:a2- b2=(a - b) (a + b)Solution:1−x41+x÷1+x2x×1x(x−1)\frac{1 - x^4}{1 + x} \div \frac{1 + x^2}{x} \times \frac{1}{x(x - 1)}1+x1−x4÷x1+x2×x(x−1)1=(1+x)(1−x)(1+x2)(1+x)÷1+x2x×1x(x−1)=\frac{(1+x)(1 - x)(1 + x^2)}{(1+x)} \div \frac{1 + x^2}{x} \times \frac{1}{x(x - 1)}=(1+x)(1+x)(1−x)(1+x2)÷x1+x2×x(x−1)1=(1−x)(1+x2)1×x1+x2×1x(x−1)= \frac{(1 - x)(1 + x^2)}{1} \times \frac{x}{1 + x^2} \times \frac{1}{x(x - 1)}=1(1−x)(1+x2)×1+x2x×x(x−1)1 =(1−x)×x×1x(x−1)=(1 - x) \times x \times \frac{1}{x(x - 1)}=(1−x)×x×x(x−1)1=(−(x−1))×x×1x(x−1)=(- (x - 1)) \times x \times \frac{1}{x(x - 1)}=(−(x−1))×x×x(x−1)1 = −1