If $$\sin(x - y) = 1/2$$ and $$\cos(x + y) = 1/2$$, then what is the value of $$\sin x \cos x - 1\sin^{2}x - \cos^{2}x \sec x$$?

A

2

B

3/4

C

$$\surd{2} + 1$$

D

1