What is a motherboard?

• A. The metal frame that supports airflow channels.
• B. The central Processing Unit that executes instructions.
• C. The main PCB that interconnects CPU(s), memory, storage, NICs, and expansion cards via buses and chipsets.
• D. The controller logic that handles I/O, storage, PCIe lanes, and legacy interfaces between CPU and peripherals.

Answer: (C)

The motherboard is the central printed circuit board that ties all the major computer components together. It provides the CPU socket, memory slots, storage interfaces, network and expansion card connectors, and uses buses and a chipset to coordinate communication between processing, memory, storage, and I/O. This broad role of unifying these parts on one board is what makes it the main backbone of the system. The other descriptions point to specific parts—the chassis frame for airflow, the CPU itself, or a subset of controller logic—rather than the board that hosts and interconnects everything.