In a $$\Delta PQR$$, if $$3\sin P + 4\cos Q = 6$$ and $$4\sin Q + 3\cos P = 1$$, then the angle $$R$$ is equal to

A

$$\frac{5\pi}{6}$$

B

$$\frac{\pi}{6}$$

C

$$\frac{\pi}{4}$$

D

$$\frac{3\pi}{4}$$