正解:C
Proper ventilation is a factor that can extend the life of a device by preventing overheating and thermal damage to the device's components. Proper ventilation means ensuring that there is enough airflow around and inside the device to dissipate heat and maintain a suitable temperature for optimal performance. Proper ventilation can be achieved by using fans, heat sinks, vents, or liquid cooling systems, as well as avoiding placing the device near heat sources or in enclosed spaces. Battery backup, electrostatic discharge mat, and green disposal are not factors that can extend the life of a device.