Utilize the input text as a context reference, choose the right relationship between Aurizon and coal from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

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.

Answer: product_or_material_produced