I came up with (a) as well. The mnemonic for that is Cadburys Dairy Milk Very Tasty.
Compass Hdg 195
Drift 8R
Compass Track 203
Deviation -2, so
Compass Track 201 Magnetic
If this is equal to a True Track of 180 True
The variation= -21
Remember to apply the Cadburys Dairy Milk Very Tasty from left to right as you read it- C>D>M>V>T and memorise:
Variation West, Magnetic Best
Variation East, Magnetic Least
(applies for Deviation too)
(does anyone know what I'm talking about?). That was quite an exercise for my brain cells after all these years! Have I made a boob above?