Question

Which sentence shows correct use of dashes?

Answer 1

Transforming disaster into opportunity—did you hear what happened?—has made him a hero.  is the correct answer. simply because it is asking if you have heard what happened then continues with the rest of the sentence and has correct punctuation for the situation.

Answer 2

The answer is the last one, which is "Transforming disaster into opportunity-did you hear what happened?- has made him a hero". As you can see transforming disaster into opportunity has made him a hero is a sentence by itself. "Did you hear what happened?" Is just extra info that goes between dashes.