Final answer:
A set-top box should have adequate space around it for proper airflow, should not be placed near a heat source, and should be cleaned regularly. Option B,C are correct.
Step-by-step explanation:
For a set-top box (STB) to have its operating temperatures maintained as specified by the manufacturer, it is important that it:
Have adequate space around it for airflow to ensure it doesn't overheat.
Not be positioned on or near a heat source, as excess heat can cause malfunction or damage.
Be cleaned regularly, although the use of electrostatic devices isn't specifically necessary unless recommended by the manufacturer.
Be plugged into a power outlet, which may or may not need to be switched, depending on the user's preference and the manufacturer's advice.
Always ventilate and follow manufacturers' instructions when using appliances to prevent pollutant build-up and overheating, which can affect their performance and lifespan.
Whether it needs to be plugged into a switched power outlet is up to user preference and manufacturer advice.