The nonrenewable resource that is most commonly used to generate electricity in Washington, based on the provided data, is D. nuclear/uranium with an electricity generation of 844,000 megawatts times hours.
However, if considering nonrenewable resources specifically and excluding hydroelectric (which is renewable) and timber (which is also renewable), natural gas (574,000) and coal (407,000) would also be contenders. Among all options given, A. coal and B. natural gas would be classified as nonrenewable resources. But if we strictly consider the most commonly used nonrenewable resource by the amounts shown, it would likely still steer towards the higher generation figures of either coal or natural gas.
So for the final context of just nonrenewable resources: B. natural gas (574,000) is often emphasized for current usage but nuclear has the highest generation. Therefore, if you're looking strictly based on the highest amounts and classifying them: D. nuclear/uranium (844,000): However, for commonality, it's still good to refer to the state reliance on natural gas at B. natural gas (if you're considering usage pattern trends).
In conclusion, the direct answer to the question based on the figures you provided would be D. nuclear/uranium, while noting other resources alongside it.