Find the Derivative of the Function $r ( x ) = \left[ \ln \left( x ^ { 8 } \right) \right] ^ { 3 }$

Multiple Choice

Find the derivative of the function.
$r ( x ) = \left[ \ln \left( x ^ { 8 } \right) \right] ^ { 3 }$

A) $\frac { 24 \left[ \ln \left( x ^ { 7 } \right) \right] ^ { 2 } } { x ^ { 8 } }$
B) $\frac { 24 \left[ \ln \left( x ^ { 8 } \right) \right] ^ { 2 } } { x ^ { 8 } }$

C) $\frac { 24 \left[ \ln \left( x ^ { 8 } \right) \right] ^ { 2 } } { x }$
D) $\frac { 24 \left[ \ln \left( x ^ { 8 } \right) \right] ^ { 3 } } { x ^ { 8 } }$
E) none of these