Evaluate the Line Integral Along the Curve C $\int _ { C } \left( \frac { x ^ { 2 } + y ^ { 2 } } { z ^ { 2 } } \right) d s , C$

Evaluate the line integral along the curve C.
- $\int _ { C } \left( \frac { x ^ { 2 } + y ^ { 2 } } { z ^ { 2 } } \right) d s , C$ is the curve $r ( t ) = ( 6 - t ) i - j + ( 6 - t ) k , 0 \leq t \leq 1$

A) $\frac { 31 } { 30 }$
B) $\frac { 31 } { 15 }$
C) $\frac { 31 } { 30 } \sqrt { 2 }$
D) $\frac { 11 } { 6 } \sqrt { 2 }$