A vessel is heading magnetic east and its magnetic compass indicates a heading of 086°.Which action should be taken to remove this error during compass adjustment（）.
A.If the blue ends of the magnets are aft，and the fore-and-aft tray is at the top，you should add some magnets
B.If the blue ends of the magnets are aft you should lower the fore-and-aft tray
C.If the blue ends of the magnets are aft，and the fore-and-aft tray is at the top，you should reverse the magnets
D.If the blue ends of the magnets are forward，and the fore-and-aft tray is at the bottom，you should add some magnets