The total magnetic effects which cause deviation of a vessel's compass can be broken down into a series of components which are referred to as __________.

Correct Answer: Option B — coefficients

The magnetic deviation of a compass is mathematically expressed as a series of coefficients (A, B, C, D, and E). These coefficients represent the various components of the vessel's magnetic field, as defined in Bowditch, Volume I, to facilitate systematic analysis and compensation of the compass.