Determine the Values Of $c$ Such That $\| c \mathbf { u } \| = 6$

Multiple Choice

Determine the values of $c$ such that $\| c \mathbf { u } \| = 6$ , where $\mathbf { u } = 6 \mathbf { i } + 5 \mathbf { j } + 5 \mathbf { k }$ .

A) $c = \pm 6$
B) $c = \pm \frac { 3 \sqrt { 86 } } { 43 }$
C) $c = \pm \frac { \sqrt { 86 } } { 6 }$
D) $\quad c = \pm \frac { 1 } { 6 }$
E) $c = \pm \frac { \sqrt { 86 } } { 86 }$