put all non-reusable glass in the trash. pour all used chemicals down the sink. collect and store recyclable material. return used samples to natural settings.
I gave my students this multiple choice question: The correct procedure after completing a laboratory experiment is to

Only one answer is correct among these 4 choices:
- put all non-reusable glass in the trash.
- pour all used chemicals down the sink.
- collect and store recyclable material.
- return used samples to natural settings.

Could you tell me which one is correct?

collect and store recyclable material.