The dialogue is roughly the following:
- Are there more [bombs]?
- [Yes, they are] covering their tracks.
- Taking out the audience?
- They're just the cheap seats.
As I previously pointed out, this signals to things:
1. The bombs are planted next to the cheap seats in the auditorium, so that we - as viewers - feel that whoever is orchestrating this fake terrorist attack don't care about innocent victims. They are willing to kill "everyone" to cover up their tracks, as the cheaps seats are taken up by those who can't afford more expensive ones, so they are really just your average people.
2. This fact also makes it easier for JDW and crew to retrieve the bombs because JDW tells them they have to look for the cheap seats - and this is exactly what they do afterwards.
- Are there more [bombs]?
- [Yes, they are] covering their tracks.
- Taking out the audience?
- They're just the cheap seats.
As I previously pointed out, this signals to things:
1. The bombs are planted next to the cheap seats in the auditorium, so that we - as viewers - feel that whoever is orchestrating this fake terrorist attack don't care about innocent victims. They are willing to kill "everyone" to cover up their tracks, as the cheaps seats are taken up by those who can't afford more expensive ones, so they are really just your average people.
2. This fact also makes it easier for JDW and crew to retrieve the bombs because JDW tells them they have to look for the cheap seats - and this is exactly what they do afterwards.