question_answer

                                                     Simplified form of \[\left( \mathbf{1 + co}{{\mathbf{t}}^{\mathbf{2}}}\theta  \right)\mathbf{ }\left( \mathbf{1 - cos }\theta  \right)\mathbf{ }\left( \mathbf{1 + cos }\theta  \right)\]is ______

A)   1        

B) 0           

C)  \[Cosec\text{ }\theta ~~~~~\]                                    

D)  \[Sin\text{ }\theta ~~~~~~~~\]

E)  None of these