Use the substitution u$=6+$exu$=6+$ex to evaluate the integral $$ex$6+$exdx$$ex$6+$exdx.

Select one:

a$.$

ln$|6+$ex$|+$Cln$|6+$ex$|+$C

b$.$

exln$|6+$ex$|+$Cexln$|6+$ex$|+$C

c$.$

$$ln$|6+$ex$|+$C$$ln$|6+$ex$|+$C

d$.$

None of the above