a) Censorship is the prohibition of parts of books, films, news, etc. that are considered obscene, politically unacceptable, or a threat to society.

b) The difference is a challenged book is something that is reluctantly accepted to a city, school, library, etc. where as a banned book is something that is not allowed in a specific state, country, city, school etc. because of the intense profanity and sexuality it holds.

c) “To kill a Mocking Bird” was both a challenged and banned book in some countries and cities because it contains violence, some profanity, racism, and death.

d) “Fahrenheit 451” might be banned or challenged because of the violence, brutality, and death it has in it.