Which of the Following Is Equal to Limit $\lim _ { x \rightarrow 0 } \frac { \cos ^ { 2 } ( 3 x ) - 1 } { 5 x }$

Multiple Choice

Which of the following is equal to limit $\lim _ { x \rightarrow 0 } \frac { \cos ^ { 2 } ( 3 x ) - 1 } { 5 x }$ ?

A) $- \frac { 6 } { 5 }$
B) $- \frac { 5 } { 6 }$
C) 0
D) $\frac { 5 } { 6 }$
E) $\frac { 6 } { 5 }$