Though I can't see all the answers here's my take:
The author was making a point that Voltaire's humor was not welcomed because it criticised their beliefs and the book was banned because it was full of his criticising humor that they did not appreciate.
His being a world war II navy veteran.
Military service has never been a challenge for any presidential candidate. People who serve are generally regarded by the American people as good and brave. Therefore it would have helped his campaign, not hurt it.
C. by describing the character's appearance and social status
Answer: Theme
Explanation:
The simply refers to the main idea that the writer wants to explore in a story, novel, or other literary work. It should be noted that the theme of a particular story can be conveyed through the use of setting, plot or dialogue.
Therefore, "This book is a warning to the living that atrocities like the Holocaust can happen and will happen again if we are not vigilant" is a theme as it expresses the idea of the writer.