What is the The United States Air Force a branch of? What groups of people get a discount at Dunkin Donuts? Is there any overlap between #1 and #2?
United States Air Force
The United States Air Force is part of the military. Dunkin Donuts offers a military discount. 
Air and space warfare branch of the United States Armed Forces
Would a member of the United States Air Force get a discount at Dunkin Donuts?