Determine the exact value of the following expression without the help of the calculator. Write your answer as a single fraction.
sin (3π/2) cos (π/3) - cos (π/6) sin (3π/4)

• A. (2 + √6)/4
• B. (-2 - √6)/4
• C. (2 - √6)/4
• D. (-2 + √6)/4

Answer: (B)