Answer:
Phaedrus was used to his student's usually having troubles finding a intresting topic to right about, or that they would choose inapropriate subjects. But he really got frustrated this time with a girl that couldn't come up with a better idea than to write an essay about the United States.
Explanation:
Choosing that subject according to Phaedrus was shown of an impediment to interpret the world beyong the objetive lense. This girl couldn't complete a writting assignment, and only came up with this 500-word essay topic of the United States. He thought of this as an impediment to make sense of the world in a more profound and less superficial way.