Because the author has researched the area and talked to people who know the land
A participle has the following form: verb + -ing, and the only word in this sentence that takes that form is A, 'flying', which is the correct answer.
Answer: "It's essential to remember that, much like ourselves, refugees are only trying to survive in this often harsh and cruel world. It's illogical to refuse entry to a group of people with the thought process of 'they're going to replace us'. If you disagree, then perhaps you should put yourselves in their shoes. Or, it may even be necessary to think back to a time when you <em>yourself</em> were in need of assistance or battled discrimination. As long as we're able to remain open-minded about Europe's refugees and understand the valid reasons for their crossing over, then none of us should have a problem with it."
Explanation: