Use an Addition or Subtraction Formula to Find the Solutions $[ 0 , \pi )$

Multiple Choice

Use an addition or subtraction formula to find the solutions of the equation that are in the interval $[ 0 , \pi )$ . $\cos 8 t \cos 5 t = - \sin 8 t \sin 5 t$

A) $t = \frac { \pi } { 6 } , t = \frac { \pi } { 2 } , t = \frac { 5 \pi } { 6 }$
B) $t = \frac { 3 \pi } { 5 } , t = \frac { 4 \pi } { 5 }$
C) $t = \frac { \pi } { 3 } , t = \frac { 2 \pi } { 3 }$
D) $t = \frac { \pi } { 8 } , t = \frac { 3 \pi } { 8 } , t = \frac { 5 \pi } { 8 }$
E) $t = 0 , t = \frac { \pi } { 3 } , t = \frac { 2 \pi } { 3 }$