If \[\mathbf{A=}\frac{\mathbf{1}}{\mathbf{1+sin }\theta }\mathbf{+}\frac{\mathbf{1}}{\mathbf{1-sin }\theta }\], then A equals to _________ .

• A. \[{{\sec }^{2}}\theta \]                                    
• B.  \[2{{\sec }^{2}}\theta \]
• C.  \[{{\cos }^{2}}\theta \]                                               
• D.  \[2{{\cos }^{2}}\theta \]
• E.  None of these