Answer:
1. son
2 is confusing this is dificult because the verbs are not correctly spelled
2. No, no traiga la mostaza ...
3. No, no saquen los fósforos ...
4. No, no busques un parque para la fogata ...
5. No, no sirvan las chuletas ...
6. No, no dejen los fósforos ...
quien is singular and quienes is plural (sorry i didn’t spell it right i couldn’t figure out how to place accents)