$$\frac{\cosec \theta}{\cosec \theta - 1} + \frac{\cosec \theta}{\cosec \theta + 1} - \tan^2 \theta, 0^\circ < \theta < 90^\circ$$, is equal to:

A

$$\sec^2 \theta + 1$$

B

$$\sec^2 \theta$$

C

$$2 \sec^2 \theta$$

D

$$1 - \tan^2 \theta$$