Compute $f ^ { \prime } ( a )$ For $a = 6$

Multiple Choice

Compute $f ^ { \prime } ( a )$ for $a = 6$ .
$f ( x ) = \frac { 5 } { x }$

A) $- \frac { 1 } { 36 }$
B) $\frac { 5 } { 36 }$
C) $5$
D) $- \frac { 11 } { 36 }$
E) $- \frac { 5 } { 36 }$