What is the value of |X( )| given X( )=1/(1-ae-j ), |a|<1?

• A. ( frac{1}{ sqrt{1-2acos +a^2}} )
• B. ( frac{1}{ sqrt{1+2acos +a^2}} )
• C. ( frac{1}{1-2acos +a^2} )
• D. ( frac{1}{1+2acos +a^2} )