Find the Second Derivative of the Function $f ( x ) = 7 ^ { x }$

Multiple Choice

Find the second derivative of the function $f ( x ) = 7 ^ { x }$ .

A) $f ^ { \prime \prime } ( x ) = ( \ln 7 ) 7 ^ { x }$
B) $f ^ { \prime \prime } ( x ) = ( \ln 7 ) ^ { 3 } 7 ^ { x }$
C) $f ^ { \prime \prime } ( x ) = ( \ln 7 ) ^ { 2 } 7 ^ { x }$
D) $f ^ { \prime \prime } ( x ) = ( \ln 7 ) ^ { 2 } 7 ^ { 2 x }$
E) $f ^ { \prime \prime } ( x ) = ( \ln 7 ) ^ { 3 } 7 ^ { 3 x }$