The plane of dip circle is set in the geographic meridian and the apparent dip is `theta_(1)`. It is then set in a vertical plane perpendicular to the geographic meridian. Now, the apparent dip is `theta_(2)`. The angle of declination `theta` at that place is

Options

A. `tan alpha=sqrt((tan theta_(1) tan theta_(2)))`
B. `tan alpha=tan theta_(1)//tan theta_(2)`
C. `tan alpha=(tan^(2) theta_(1)+tan^(2) theta_(2))`
D. `tan alpha= tan theta_(2)//tan theta_(1)`