Which of the following would BEST be described as Preventative Maintenance?

Preventative maintenance encompasses actions taken to prevent failures or breakdowns before they occur, thereby ensuring the continuous operation and efficiency of equipment. Lubricating the bearings is an excellent example of preventative maintenance because it is a proactive measure that reduces friction and wear on moving parts, thus extending the lifespan of machinery and minimizing the likelihood of unexpected equipment failure. Regular lubrication helps maintain optimal performance and reduces the need for more extensive repairs, making it a key practice in a preventative maintenance program.

Other activities, while also important for maintenance, are often considered reactive or regular maintenance tasks. Regularly changing filters, inspecting for leaks, and cleaning the aeration system are necessary actions, but they address either ongoing operation or issues after they arise rather than taking proactive steps to prevent them in the first place.