A dip needle lies initially in the magnetic meridian when it shows an angle of dip \[\theta \] at a place. The dip circle is rotated through an angle \[x\] in the horizontal plane and then it shows an angle of dip\[\theta '\]. Then \[\frac{\tan \theta '}{\tan \theta }\]is

• A. \[\frac{1}{\cos x}\]        
• B. \[\frac{1}{\sin x}\]
• C. \[\frac{1}{\tan x}\]        
• D. \[\cos x\]