He ridiculed and called Christoffels names.
Answer: Option 4.
Step-by-step explanation:
Otto persecuted Christoffels. He persecuted Christoffels by ridiculing him and he thought that there was no need of him to respect Christoffels. So he persecuted him and did not respect him.
Even though father of Christoffels was Otto's boss, then also Otto thought that there was no need of him to respect Christoffels. Otto had the thinking in his mind that he only had to respect Christoffels' father because he was his boss and no need to respect Christoffels. So he persecuted him by ridiculing him.