Multiply the following polynomials:

\[3x^3(5x^2+4x)\]

A. \[8x^6 + 7x^3\]

B. \[15x^6 + 12x^4\]

C. \[15x^6 + 12x^3\]

D. \[15x^5 + 12x^4\]

E. \[8x^5 + 7x^4\]

F. \[15x^5 + 12x^3\]