If $$1 + \sin \theta = m\cos\theta$$, then what is the value of $$\sin \theta$$?

A

$$\frac{2m^{2} - 1}{m^{2} + 1}$$

B

$$\frac{m^{2} - 1}{m^{2} + 1}$$

C

$$\frac{m^{2} + 1}{2m^{2} - 1}$$

D

$$\frac{m^{2} + 1}{m^{2} - 1}$$