poured the chemicals down the sink drain. placed the chemicals carefully in the trash can. placed each chemical back in its original container. followed the directions provided by the teacher for each chemical.
I gave my students this multiple choice question: Students finished a laboratory experiment using chemicals. The students made sure they safely disposed of the chemicals because they

Only one answer is correct among these 4 choices:
- poured the chemicals down the sink drain.
- placed the chemicals carefully in the trash can.
- placed each chemical back in its original container.
- followed the directions provided by the teacher for each chemical.

Could you tell me which one is correct?

followed the directions provided by the teacher for each chemical.