Final answer:
The technique being used is foreshadowing, which provides hints about future plot developments, distinct from flashbacks which revisit past events.
Step-by-step explanation:
If the author tells about an accident that led to the deaths of his wife and daughter in the opening paragraph, the technique being used is foreshadowing. This method involves giving hints or clues about plot developments that will occur later in the narrative. It's a way for the author to build suspense or prepare the reader for what is to come. An example in literature is when a character drops a seemingly innocuous comment that hints at future events. Unlike flashbacks, which look back at past events, foreshadowing looks ahead to create anticipation or dread in the reader's mind.