Who qualifies as a Miner according to the definitions provided?

The correct choice identifies a Miner as an individual working underground who is certified. This definition emphasizes the specialized nature of underground mining work, which typically requires specific training and certification to ensure safety and operational competence. Miners are responsible for various tasks related to the extraction of minerals and maintaining safe working conditions in an underground environment.

Certification is a critical aspect because it signifies that the individual has met the necessary training requirements, understands the hazards associated with underground mining, and is knowledgeable about safety protocols. This definition also helps to delineate the role of a Miner from others within the mining industry, such as those involved in surface mining, overseeing operations, or administrative roles, which do not require the same level of training specific to underground mining environments. Therefore, the focus on certification and underground work within this definition is what makes it the appropriate characterization of a Miner.