For the year 2018, I worked as a contractor on an APO in Kuwait ( military base.)
Which of these options would apply to me?
As a contractor working on a military base and if you receive a W-2 you would check "Worked outside the U.S. - I worked outside the U.S. for an employer that wasn't the U.S. government or its agencies" after entering your W-2. And you might qualify for the Foreign Earned Income Credit. Please see this FAQ: