Integrate $\int \frac{4 x}{x^{2}+1} d x$ A) $4 \operatorname{Arctan} x+C$ B) $2 \ln \left(x^{2}+1\right)+C$

Integrate $\int \frac{4 x}{x^{2}+1} d x$

A) $4 \operatorname{Arctan} x+C$
B) $2 \ln \left(x^{2}+1\right) +C$
C) $4 \ln \left(x^{2}+1\right) +C$
D) $\frac{1}{2} \ln \left(x^{2}+1\right) +C$