Out of the options you provided, the correct answer would be B. "But he stepped out briskly, breathing deeply of the cold air" is not strictly factual because it does not contain a specific time, location, date or object!
They weren't seen as a threat because they lived on a far away island separated from the continental United States. The fear was that people on the mainland could be spies or could participate in sabotages or similar things, while people on Hawaii were more or less isolated from the remainder of America and did not pose a threat at all.
