It relates his book to the past, and how in some aspects, he thinks we haven't learned anything. There's still Nazis today, called "neo-nazis", and he believes that they are completely psychotic. He gives the audience his opinion, and uses evidence to back it up.
Hope this helps!
"I could hear a small inner voice crying, ‘Don’t! Don’t!’"
The answer is A.) to motivate employers and employees to laugh it up for good health and business