Prescott quietly slipped out of Aurizon last week, and the public formalities of Monday's obviously solid annual results announcement provided a timely platform for chief executive Lance Hockridge to reassert a recovery of focus on his core coal business and on sating senior owners' expectations that he is running an annuity investment.
Analyze the relationship between 'Aurizon' and 'coal' within the context of the input sentence.
Options: operator, product/material produced, employer, manufacturer