In this task, you're given a passage, further information available on a particular linked term from the statement, and an answer term. Your job is to generate a question that can use the information provided to obtain the given answer. You should use the information on both passage and link information to create the question. Note that the answer to the question should be exactly the given answer, and if the answer is none, the answer to the question shouldn't be obtainable from the passage or linked information.
Q: Passage: After the D-Day invasion, was reassigned to IX Tactical Air Command (IX TAC) and directed to provide ground support for advancing United States First Army forces in France, attacking enemy targets initially in the Cotentin Peninsula, then supported Operation Cobra, the breakout of Normandy and attacked enemy forces in the Falaise-Argentan Gap. Wing headquarters and subordinate units operated primarily from liberated airfields and newly built temporary Advanced Landing Grounds in France, moved into north-central France, its groups attacking enemy targets near Paris then north-west into Belgium and the southern Netherlands. In December 1944/January 1945, engaged enemy targets on the north side of the Battle of the Bulge, then moved eastward into the Northern Rhineland as part of the Western Allied invasion of Germany.
Link Information: The Falaise Pocket or Battle of the Falaise Pocket (; 12 21 August 1944) was the decisive engagement of the Battle of Normandy in the Second World War. Answer: 1944
A:
What year was the battle of the Gap?