Answer:
The statement that best explains the situational irony is: "The smaller girl made no actual comment on the story, but she had long ago recommenced a murmured repetition of her favourite line".
Step-by-step explanation:
A situational irony refers to a situation that turns out the opposite from what was intended. In the passage, the three kids are noisy and asking questions, so the aunt tries to calm them down with a storytelling, but the result is that her story is boring and "stupid" as the small girl, Cyril, says.
Nevertheless, the best statement that shows the situational irony is the one in which the smaller girl simply keeps on what she was doing: repeating her favorite line from the poem "On The Road to Mandalay", for the aunt did not captivated her attention even a little, and that is a sign that the aunt's intention did not ended as she expected at all.