The value of cos\[\theta \] in terms of tan\[\theta \] is

• A.  \[\frac{1}{\sqrt{1-{{\tan }^{2}}\theta }}\]                                            
• B. \[\frac{1}{\sqrt{1+{{\tan }^{2}}\theta }}\]        
• C.  \[\frac{\sqrt{1-{{\tan }^{2}}\theta }}{\sqrt{1+{{\tan }^{2}}\theta }}\]                                                 
• D.  \[\frac{1}{\sqrt{3-3{{\tan }^{2}}\theta }}\]
• E.   None of these