Hàm số f(x) = cos^2(x^2+1) có đạo hàm là f'(x) = -2x sin2 (x^2 +1)

A. $f^{\text{'}}\left(x\right)=-4x\sin 2\left(x^2+1\right)$

B. $f^{\text{'}}\left(x\right)=2\cos \left(x^2+1\right)$

C. $f^{\text{'}}\left(x\right)=2x\sin 2\left(x^2+1\right)$

D. $f^{\text{'}}\left(x\right)=-2\text{x}\sin 2\left(x^2+1\right)$