A dip needle lies initially in the magnetic meridian when it shows an angle of dip $\mathrm{\theta }$ at a place. The dip circle is rotated through an angle x in the horizontal plane and then it shows an angle of dip ${\mathrm{\theta }}^1$. Then $\frac{{\mathrm{tan\theta }}^1}{\mathrm{tan\theta }}$ is

• A

  $\frac{1}{\cos x}$

• B

  $\frac{1}{\sin \mathrm{x}}$

• C

  $\frac{1}{\tan \mathrm{x}}$

• D

  cos x