Final answer:
The primary reason California has so many wildfires is prolonged drought and dry conditions.
Step-by-step explanation:
The primary reason California has so many wildfires is d. Prolonged drought and dry conditions. California experiences long periods of dry weather, with little rainfall and high temperatures, which create ideal conditions for wildfires to start and spread rapidly. The dry conditions lead to dry vegetation, making it easier for fires to ignite and for them to spread quickly.