Which piece of evidence from the article BEST explains the cause of the wildfires in California?

A. Anything with a spark can start a fire. A carelessly littered cigarette, a fallen power line or a car's backfire can all spark.

B.California's most dangerous wildfire season comes in autumn because of a few reasons.

C. The abundance of dry vegetation combined with low humidity and unusually high winds up to 79 mph have led to fast-moving infernos.

D.They are spread over a 200-mile region north of San Francisco starting with Napa in the south extending to Redding in the north.