Choose the sentence with the correct use of a dash.

1. ক
   The three candidates—John, Sarah, and Mike—are waiting outside.
   
2. খ
   The three candidates—John, Sarah, and Mike, are waiting outside.
   
3. গ
   The three candidates, John, Sarah, and Mike—are waiting outside.
   
4. ঘ
   The three candidates—John, Sarah, and Mike are waiting outside.