You can infer they were impressed because of seeing something unusual
The answer is B I think sorry if it’s not
Cause and appear because these words need to be singular since the other words are plural
Key themes of the Romantic Period
Revolution, democracy, and republicanism. ...
The Sublime and Transcendence. ...
The power of the imagination, genius, and the source of inspiration. ...
Proto-psychology & extreme mental states. ...
Nature and the Natural.
If you don't have answer choices, I would say either peer editing or reading it aloud and listening for errors.