During underground inspections, which item relates to gas drainage?

• A. Gas drainage sites range and monitoring.
• B. Fire extinguisher.
• C. Electrical wiring.
• D. Drinking water supply.

Answer: (A)

Gas drainage aims to reduce methane concentrations by draining gas from the coal seam and surrounding rock through boreholes. In underground inspections, you assess how widely the drainage system covers the area (the range of drainage sites) and how gas flow and gas concentrations are monitored. This directly relates to managing gas in the mine, which is why the option describing gas drainage sites range and monitoring is the best fit. The other items—fire extinguisher, electrical wiring, and drinking water supply—address different safety or facility needs and aren’t specifically about controlling gas levels.