Answer:
The correct answer is Stanley’s grandfather falling in love with Myra Menke.
Step-by-step explanation:
A flashback is a narrative technique (literary, cinematographic ...) that takes the temporal narration back to a past event, almost always with the intention of locating something important for the configuration of the present character or situation developed.
In the book Holes, the use of this technique is what makes the reader have more than one time frame and perspective.
In this chapter, the story of Stanley's family is developed a little more, in this case that of his grandfather.