In 2007, the United States Marine Corps began to transition from the RQ-2 Pioneer to the RQ-7 Shadow. VMU-1, VMU-2 completed their transition from the RQ-2 to the RQ-7 and Boeing ScanEagle while VMU-3 and VMU-4 were activated as Shadow and ScanEagle elements. VMU-3 was activated on 12 September 2008 and VMU-4 conducted its inaugural flight on 28 September 2010 in Yuma, Arizona. In October 2007, VMU-1 became the first Marine Corps squadron to see combat in Iraq. VMU-2 deployed a Shadow detachment to Afghanistan in 2009, with VMU-3 following in January 2010.
Question: Which VMU was activated on the 12 of September, VMU-3 or VMU-4?
Answer: VMU-3