question_answer

The  expression \[\frac{\cos 6x+6\cos 4x+15\cos 2x+10}{\cos 5x+5\cos 3x+10\cos x}\]

A)  \[\cos 2x\]        

B)  \[2\cos x\]

C)  \[{{\cos }^{2}}x\]      

D)  \[\cos x\]