Final answer:
The situational irony in the passage is that the aunt does not expect the bachelor to tell a story, but he does.
Step-by-step explanation:
The situational irony that occurs in the passage is option D: The aunt does not expect the bachelor to tell a story, but he does.
In the passage, the aunt challenges the bachelor's storytelling abilities, claiming that it is difficult to tell stories that children can both understand and appreciate. The bachelor disagrees and offers to tell a story. However, the children quickly lose interest, finding all stories to be similar regardless of who tells them. This is ironic because the aunt did not expect the bachelor to actually tell a story, but he does.
This situational irony adds humor to the passage by highlighting the contrast between the aunt's challenge and the bachelor's unexpected response.