The problem $2$x$+31+$x$2$dx can be split, like this:$2$x$1+$x$2$dx$+311+$x$2$dx $.$

What is the result of integrating both "smaller" problems?

Group of answer choices

$2$x$1+$x$2$dx$+311+$x$2$dx$=2$x$$ln$(1+$x$2)+3$ln$(1+$x$2)+$C $$

$2$x$1+$x$2$dx$+311+$x$2$dx$=$x$2+$ln$|$x$|+3$arctanx$+$C$$

$2$x$1+$x$2$dx$+311+$x$2$dx$=$ln$(1+$x$2)+3$arctanx$+$C