Multiply the Following $\left( - 9 x ^ { 5 } b ^ { 5 } \right) ( 8 x b )$

Multiple Choice

Multiply the following. $\left( - 9 x ^ { 5 } b ^ { 5 } \right) ( 8 x b )$

A) $- 69 x ^ { 6 } b ^ { 6 }$
B) $- 74 x ^ { 6 } b ^ { 5 }$
C) $- 72 x ^ { 5 } b ^ { 6 }$
D) $- 72 x ^ { 6 } b ^ { 6 }$