Evaluate the indefinite integral $$dx$(5$x$3)2$dx$(5$x$3)2.$

Select one:

a$.$

$15(5$x$3)+$C$15(5$x$3)+$C

b$.$

$15$x$3+$C$15$x$3+$C

c$.$

$15$x$3+$C$15$x$3+$C$$

d$.$

None of the above