Explanation:

The correct option is (D) circuit board that contains a CPU and other chips. The motherboard is the main printed circuit board (PCB) in a computer. It acts as the central communication backbone, connecting all of the computer's essential components, including the Central Processing Unit (CPU), memory (RAM), storage devices, and expansion cards. It provides the electrical connections and physical support for these components. Option (A) is partially correct as it provides connections for peripheral devices, but its primary definition is broader. Option (B) is incorrect; the CPU chip is a single component that resides *on* the motherboard, not synonymous with it. Option (C) refers to the BIOS (Basic Input/Output System) chip, which is accessed first during boot-up, but the motherboard itself is not 'the first chip'.