Choose the One Alternative That Best Completes the Statement or Answers

Multiple Choice

Choose the one alternative that best completes the statement or answers the question.
Divide
- $\frac{21 x^{5}+21 x^{4}+24 x^{3}}{3 x^{4}}$

A) $15 x+7$
B) $7 x+7$
C) $7 x+21 x^{4}+\frac{8}{x}$
D) $7 x+7+\frac{8}{x}$