- AThe classroom has no lights or fans
- BLights and fans are sometimes left on when classrooms are empty
- CElectricity is supplied free to the school
- DStudents never follow any instructions
Step-by-Step Solution
The notice makes sense only if there is a real chance of lights and fans being left running in empty rooms; that possibility is the implicit assumption.
Answer: B) Lights and fans are sometimes left on when classrooms are empty