In a personal computer, which of the following components controls and coordinates communications between the various parts of the entire computer system?

Introduction / Context:
Inside a computer, different components such as the processor, memory, storage devices, and input or output ports must communicate with one another. This communication depends on physical connections and electronic pathways that carry data and control signals. Understanding which main component provides the central platform for these connections helps clarify how the computer system works as a whole.

Given Data / Assumptions:

• The question asks which part “controls communications for the entire computer system”.
• The options are arithmetic-logic unit, semiconductor, motherboard, and coprocessor.
• We assume a typical desktop or laptop architecture with a central main board.
• Control of communications here refers to the physical and logical interconnection of components.

Concept / Approach:
The motherboard is the main circuit board in a computer. It holds the CPU socket, memory slots, chipset, expansion slots, and connectors to storage and input or output ports. It contains buses and electronic pathways that carry data and control signals between all major components. While the CPU and its arithmetic-logic unit perform calculations and control instructions, the motherboard provides the communication infrastructure that links everything together. A semiconductor is a material type, not a specific component. A coprocessor is an additional processor that assists the main CPU but does not itself form the communication backbone. Therefore, the component that controls and coordinates communications for the entire system is the motherboard.

Step-by-Step Solution:
Step 1: Consider the role of the arithmetic-logic unit. The arithmetic-logic unit performs arithmetic and logical operations inside the CPU; it does not provide system wide wiring. Step 2: Consider “semiconductor”. This is a type of material used to build chips, not a specific communication controller for the whole system. Step 3: Consider the motherboard. The motherboard carries buses and connectors that link the CPU, memory, storage devices, and peripherals, and coordinates communication between them. Step 4: Consider the coprocessor. A coprocessor is a helper processor for specialised tasks, not the central communication hub. Step 5: Conclude that the motherboard best fits the description.

Verification / Alternative check:
Hardware diagrams frequently show the motherboard at the centre, with arrows from CPU, RAM, PCIe slots, storage connectors, and I/O ports all connected to it. The motherboard chipset manages data flows between these components. When people upgrade or build computers, they choose a motherboard that supports the desired processors, memory, and expansion cards, precisely because it coordinates communication among them. In contrast, the arithmetic-logic unit is discussed within the internal organisation of the CPU, and coprocessors appear only in some systems as optional performance enhancements. This supports the motherboard as the correct answer.

Why Other Options Are Wrong:
Option A (arithmetic-logic unit): Responsible for executing arithmetic and logic instructions, but not for system wide hardware communication. Option B (semiconductor): Refers to a class of materials and devices, not a specific component that connects the entire system. Option D (coprocessor): A secondary processor that assists with specialised tasks, not the main communication backbone.

Common Pitfalls:
Students may confuse logical control with physical communication. They might think the CPU or its arithmetic-logic unit controls everything simply because it executes programs. While the CPU does issue control signals, the motherboard is the component that actually provides the wiring, buses, and connectors that enable physical communication. To avoid confusion, associate “motherboard” with the central board that ties all hardware components together.

Final Answer:
The component that controls communications for the entire computer system is the motherboard.