What is ironic about the circus workers and Mr. Sleary saving Tom at the end of the novel?

What is ironic about the circus workers and Mr. Sleary saving Tom at the end of the novel?

Gradgrind originally despised the circus, but he now has to rely on them to save Tom.

Tom does not deserve to be saved.

Tom robbed the bank and not Stephen.

Tom used to be a member of the circus, and now they are saving him.