Correct Answer - Option 4 : the true meridian and the magnetic meridian.
Explanation:
Magnetic declination:
The magnetic declination and the true meridian at a place generally do not coincide. The horizontal angle which the magnetic meridian makes with the true meridian is called the magnetic declination. If the magnetic north is to the west of the true north, the declination is said to be west or negative and if the magnetic north is to the east of the true north, the declination is said to be east or positive.
Azimuth:
The horizontal angle made by a true meridian with the survey line is called as azimuth. Azimuths are generally observed from north. Azimuths may be geodetic, astronomic, magnetic, grid, record, or assumed, depending on the reference meridian used
Magnetic bearing:
Magnetic bearing of a line is the horizontal angle which the line makes with the magnetic north. It changes with time. It is used for small areas and it is measured with the magnetic compass.
Dip:
It is the inclination of the magnetic needle with the horizontal. The dip is zero at the equator and the needle will remain horizontal.
At a place near 70° north latitude and 96° west longitude, the dip will be 90°. This area is called the magnetic north pole. Similarly, near the south magnetic pole, the dip is 90°.
