What ______________________________ hanging around in airports?

The correct answer effectively captures a more complex and nuanced sentiment about the subject of "hanging around in airports." By using the phrase "What I object to is," the answer directly states a personal objection or disapproval, indicating a clear stance on the matter. This construction is not only grammatically correct but also conveys a deeper level of engagement with the topic, reflecting a sense of personal preference or aversion that is more emphatically expressed than simply being "displeased" or "frustrated."

The other options tend to express feelings that, while valid, do not convey as strong of a personal stance as the chosen answer. Phrases like "displeases me about," "frustrates me regarding," and "upsets me about" express dissatisfaction but lack the assertiveness and clarity of an objection. They suggest a reaction to a situation rather than a decisive stance on the issue at hand. Therefore, the choice made articulates a more robust perspective on the frustration associated with hanging around in airports.