Use the Sum-To-Product Formulas to Rewrite the Sum or Difference $\cos \frac { 11 \theta } { 2 } \cos \frac { 5 \theta } { 2 }$

Multiple Choice

Use the sum-to-product formulas to rewrite the sum or difference as a product. ​
Cos 3θ + cos 8θ
​

A) ​ $\cos \frac { 11 \theta } { 2 } \cos \frac { 5 \theta } { 2 }$
B) ​ $2 \cos \frac { 11 \theta } { 2 } \sin - \frac { 5 \theta } { 2 }$
C) ​ $2 \sin \frac { 11 \theta } { 2 } \sin \frac { 5 \theta } { 2 }$
D) ​ $\cos - \frac { 11 \theta } { 2 } \cos \frac { 5 \theta } { 2 }$
E) $2 \cos \frac { 11 \theta } { 2 } \cos - \frac { 5 \theta } { 2 }$