The type of drill bit employed in wagon drill machine.

The type of drill bit commonly employed in a wagon drill machine is the X' bit with tungsten carbide.

Wagon drill machines are used for drilling blast holes in open-pit mining operations. These machines use high-pressure air to power the drill bit and are mounted on wheels or tracks for easy movement around the mining site. The X' bit with tungsten carbide is a hard and durable drill bit that can withstand the abrasiveness of rock surfaces encountered during drilling operations.

Option A, auger bit, is commonly used for drilling holes in soil, whereas option D, worm bit, is used for drilling soft materials such as wood and plastics. Option B, eccentric bit, is not commonly used in mining operations.

Therefore, the correct answer is option C, X' bit with tungsten carbide.