Answer: (C) Lightning
Step-by-step explanation:
Lightning is one of the natural causes of the wildfire as the lightning is the naturally caused wildfire. Natural flames are by and large begun by lightning, with a very little rate began by sudden ignition of dry fuel for example leaves and the sawdust.
The average 22,600 wildfire are mainly occurred due to the lightning per year. On the other hand, all the other options are incorrect as they all are the human caused wildfire.
Therefore, Option (C) is correct.