To center a compass bowl in its binnacle，you should have the ship on an even keel，heading north or south，and adjust the screws until（）.
A. the compass heading is in line with the lubber's line
B. there is no lost motion in the gimbal rings
C. no change of heading by compass is observed if you raise and lower the heeling magnet
D. the gimbal rings do not strike the compass frame when they are tilted
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