Answer:
Your answer would be that "that girl is so strong, I think she might be from the planet Krypton" is the example in which the author uses an allusion.
Step-by-step explanation:
Allusion is a literary device by which an author makes a brief and indirect reference to a person, place, idea. It does not describe the refence in detail because the author expects the reader to have the necessary background information ir order to spot the allusion and grasp its importance in the text.
In the paragraph above, "planet Kryton" is a reference to a fictional planet appearing in American comic books by Dc comics. The planet is the native world of Superman and is named after the element Krypton. As Superman home planet, people given birth there are expected to be as strong as said fictional character. That's why the author compares the girl's strength to someone from Krypton.