Question $6(5$ points$)$

Find the general indefinite integral.

${\displaystyle \underset{\phantom{}}{\overset{\phantom{}}{}}}x(85x^3)dx$

Select the correct answer.

$4x^2\frac{5}{6}{x}^{2}C$

$4x^{2}5x^{5}c$

$4x^2\frac{6}{4}{x}^{4}c$

$8x\frac{5}{6}{x}^{2}c$