Why should wall-mounted smoke detectors be placed near the ceiling?

Wall-mounted smoke detectors should be placed near the ceiling primarily because smoke rises. As materials burn, the smoke produced is hot and less dense than air, causing it to rise to the upper levels of a room. By placing smoke detectors near the ceiling, they can detect smoke more effectively and quickly, providing early warnings in the event of a fire.

This placement takes advantage of the natural behavior of smoke, maximizing the detector's functionality in identifying smoke particles before they can spread throughout the space. Additionally, other options do not address the primary purpose of smoke detectors in fire safety, making them less pertinent to optimal smoke detection practices.