Find the Indicated Product $( 4 x ) \left( - 2 x ^ { 3 } \right) \left( - 5 x ^ { 4 } \right)$

Multiple Choice

Find the indicated product. $( 4 x ) \left( - 2 x ^ { 3 } \right) \left( - 5 x ^ { 4 } \right)$

A) $40 x ^ { 7 }$
B) $40 x ^ { 8 }$
C) $- 40 x ^ { 7 }$
D) $40 x ^ { 13 }$
E) $- 40 x ^ { 8 }$