Which positions must hold certificates of competency according to mining regulations?

Certificates of competency in mining are essential for ensuring that individuals in certain positions have the required skills and knowledge to safely and effectively perform their duties. In the context of Queensland mining law, specific roles are mandated to possess these certificates due to the significant safety and operational responsibilities involved.

Selecting positions such as an underground mine manager, emergency response coordinator, ventilation officer, and fire officer is correct because these roles relate directly to safety and regulatory compliance within a mining environment, particularly underground. The underground mine manager is responsible for overseeing all mining operations in an underground setting, requiring a deep understanding of safety protocols and regulatory standards. The emergency response coordinator needs to be equipped to deal with emergencies, while the ventilation officer is tasked with ensuring that air quality standards are met, which is crucial for the health of workers. The fire officer's role involves implementing and managing fire safety protocols, which is vital for preventing accidents and ensuring worker safety.

The other options include positions that might not universally require a certificate of competency under the specific regulations governing mining operations in Queensland. While they may be important roles, they do not share the same level of regulatory compliance mandates as those in the selected answer. Hence, option C encompasses roles that are critical for ensuring the safety and regulation of mining activities underground,