Question

which mining method involves creating underground rooms with supporting pillars? room and pillar mining strip mining long - wall mining mountaintop removal

Explanation:

To solve this, we analyze each mining method:

• Room and pillar mining: Involves creating underground rooms (excavated areas) with pillars left to support the roof, matching the description.
• Strip mining: Involves removing layers of soil/rock from the surface, not underground rooms with pillars.
• Long - wall mining: Uses a long wall of machinery to mine, not creating rooms with pillars.
• Mountaintop removal: Removes the top of a mountain, surface - based, not underground room - pillar structure.

Answer:

A. room and pillar mining