The answer is B.
Ethics.
Most modern people don't have good ones.
I haven't read fahrenheit 451 in awhile, but knowing the plot/character I'm pretty sure it's A.
In O. Henry's The Ransom of Red Chief, a plan to abduct a boy and hold him for ransom goes horribly wrong. Bill apologizes for handing up the ransom when the reader and Sam can view the boy. Situational irony happens when the reverse occurs.
I hope this helps you
:)
