A company has had problems with their HVAC system being able to cool their datacenter as they have grown. Which of the following could BEST be used to help reduce the load on the HVAC system?

Replacing CAT5 cables with CAT6 cables has negligible impact on heat generation or HVAC load, as network cables contribute very little to overall datacenter heat.

Water-cooled racks are highly efficient at removing heat directly from IT equipment, significantly reducing the amount of heat released into the datacenter air. This directly lessens the burden on the overall HVAC system, making it an effective solution for high-density environments.

Turning off non-critical servers during non-business hours would reduce power consumption and heat, but it is not the best solution as it impacts availability and is less efficient than a direct cooling solution for continuous load.

Removing redundant power supplies would reduce reliability but would not significantly reduce power consumption or heat output, as the primary power supply would still be doing the work and the second PSU mostly sits idle until needed.