Question

“’[Jordan]’s a nice girl,’ said Tom after a moment. ‘[Her family] oughtn’t to let her run around the country this way.” Tom’s criticism of Jordan is ironic because…

Answer 1

As Tom says that Jordan is "running around the country", he's implying she may be doing something immoral or unethical, which contradicts his earlier thought that Jordan is a "nice girl", giving a sense of irony to the author's audience.