Which of the following is an environmental server maintenance task that should be performed every three months?

Replacing rubber mats is not a standard quarterly server maintenance task and is not directly related to the server's operational environment.

Cleaning servers to limit dust buildup is a critical environmental maintenance task that should be performed regularly, typically every three months (quarterly), to prevent overheating and maintain component longevity.

Washing the outside of servers is generally not recommended as it could introduce moisture or chemicals to sensitive electronics; dusting is preferred.

Replacing server fans is typically done only when they fail or show signs of failure, not as a routine quarterly maintenance task.