Which of the following statements with reference to isogonic line are correct in magnetic declination?
1. It is drawn through the points of same declination
2. It does not form complete great circle
3. It radiates from north and south magnetic regions and follow irregular paths
1
1 and 2 only
2
1 and 3 only
3
2 and 3 only
4
1, 2 and 3