Answer:
The statement that best descrcibes the Washington economy since World War II is c) a series of ups and downs in economic activity.
Explanation:
After World War II, Washington managed to shift from wartime production to peacetime one. Its economy was based on aircraft and ships production, so the state was benefitted not only during World War II, but also during the Cold War. However, Washington's economy was seriously affected during the 1970s, when the U.S. government cancelled its commercial jet project: the economy collapsed because one out of five jobs were tied to that industry. Eventually, Washington managed to reinvent itself and is now thriving on the technology industry, among others.