Analyzing Flashback in Narrative

In literary analysis, a flashback is often a critical narrative technique that enriches a character's development and provides layered context to the plot.

Consider the following excerpt from a fictional narrative where the protagonist, John, recalls a haunting incident from his childhood that influences his current decisions:

'As he stood at the edge of the cliff, staring at the turbulent sea below, memories of that fateful summer flooded back. He could almost hear his sister's laughter, a stark contrast to the grim reality that had followed. The sun had set on their innocence that day, engulfing them in darkness.'

Which of the following choices best describes how the excerpt uses the flashback technique?