Which of the following technologies is responsible for communication with the CPU?

eSATA is an external interface standard for connecting storage drives and does not manage CPU communication.

PCI Express is a bus interface standard for expansion cards; it connects to the Northbridge but is not itself responsible for CPU communication.

The Southbridge manages lower-speed I/O functions such as USB, audio, SATA, and PCI, communicating with the Northbridge rather than directly with the CPU.

The Northbridge (Memory Controller Hub) sits between the CPU and high-bandwidth components including system RAM and the graphics bus (AGP/PCIe), handling fast data transfers that require low latency. It forms part of the chipset and directly manages CPU-to-memory communication on legacy architectures.