When does the eruption of Cleveland Volcano happens?

Mount Cleveland Volcano in Alaska had a significant eruption in 2009, with multiple eruptive episodes throughout the year. While Cleveland Volcano has erupted in other years including 2006, 2008, and historically in 1944, 2009 was one of its most active recent periods. The question asks when the eruption happens, and 2009 is a correct answer among the options.