Let $$P = \left\{\theta : \sin \theta - \cos \theta = \sqrt{2} \cos \theta\right\}$$ and $$Q = \left\{\theta : \sin \theta + \cos \theta = \sqrt{2} \sin \theta\right\}$$ be two sets. Then

A

$$P \subset Q$$ and $$Q - P \neq \varnothing$$

B

$$Q \not \subset P$$

C

$$P \not \subset Q$$

D

$$P = Q$$