单项选择题
A.compass error B.true heading C.variation D.deviation
A.geographic pole and the magnetic pole B.lubber's line and true north C.horizontal and the magnetic line of force D.compass heading and the magnetic heading
A.varies depending upon the bearing used B.is the angular difference between magnetic north and compass north C.is published on the compass rose on most nautical charts D.is the angular difference between geographic and magnetic meridians