Choose the One Alternative That Best Completes the Statement or Answers

Multiple Choice

Choose the one alternative that best completes the statement or answers the question.
Complete the identity.
- $\sin ( \alpha + \beta ) \cos ( \alpha - \beta ) = ?$

A) $\sin \alpha \cos \alpha - \sin \alpha \cos \beta + \sin \beta \cos \alpha + \sin \beta \cos \beta$
B) $\sin ^ { 2 } \alpha \cos ^ { 2 } \beta - \sin ^ { 2 } \beta \cos ^ { 2 } \alpha$
C) $\sin \alpha \cos \alpha + \sin \beta \cos \beta$
D) $\sin ^ { 2 } \alpha - \cos ^ { 2 } \beta$