Which connector is specifically labeled as cpu_fan on the motherboard?

The correct choice identifies the heatsink power connector, which is designated as cpu_fan on the motherboard. This connector is specifically meant for the CPU cooling fan, ensuring the processor operates within optimal temperature ranges by providing the necessary power to the fan mounted on the heatsink.

The cpu_fan connector is crucial because it not only delivers power but also often features a speed sensor, allowing the motherboard's firmware to monitor the fan's operation and adjust performance as needed to prevent overheating. Maintaining proper cooling for the CPU is essential for system stability and longevity.

Other connectors, such as case fan power connectors, typically control additional fans within the computer case and are not specifically tied to the CPU. The mainboard power connector provides power to the entire motherboard rather than focusing on a specific component like the CPU. An audio header port is utilized for connecting audio devices and does not relate to power management for cooling components.