What essential component connects the CPU, memory chips, and other internal devices?

The correct choice is the motherboard, which serves as the essential component connecting the CPU, memory chips, and other internal devices within a computer system. The motherboard acts as the main circuit board that houses the CPU, RAM, and provides slots for expansion cards. It facilitates communication between these components through pathways known as buses, allowing data to be transmitted back and forth between the CPU, memory, and attached devices.

In contrast, BIOS is firmware responsible for booting up the system and ensuring hardware is functioning properly, but it does not serve as the physical connector between components. An expansion card is an additional piece of hardware that can be inserted into the motherboard to add functionality, such as graphics or sound capabilities, but it is not a primary component that connects all internal devices. The processor, while a critical component for computing tasks, specifically refers to the CPU itself and does not encompass the entire system's connectivity. Therefore, the motherboard is the fundamental component that integrates all internal parts of a computer system.