Correct Option: A. Plotter Explanation of the Correct Answer The system unit, often referred to as the computer case or chassis, is the main enclosure that houses the essential components of a computer. These components typically include:

• Motherboard: This is the main circuit board that connects all components of the computer, including the CPU, memory, and other peripherals.
• Central Processing Unit (CPU): Often called the brain of the computer, the CPU processes instructions and performs calculations.
• Storage Devices: This includes hard drives, solid-state drives, and historically, floppy disks.

Plotter is the correct answer because it is not housed within the system unit. Instead, a plotter is an external peripheral device used for printing vector graphics. It connects to the computer but operates outside of the system unit itself. Why the Other Options are Incorrect

• B. Motherboard: This is a critical component of the system unit. It serves as the backbone of the computer, allowing communication between the CPU, memory, and other hardware components. Therefore, it is definitely housed within the system unit.
• C. Floppy Disk: While floppy disks are an older form of storage, they are still considered part of the system unit when they are housed in a floppy disk drive. In modern contexts, floppy disks are less common, but they were once integral to the system unit for data storage and transfer.
• D. Central Processing Unit (CPU): The CPU is a fundamental part of the system unit. It is installed directly onto the motherboard and is essential for executing instructions and processing data. Thus, it is definitely included within the system unit.

Summary of Key Points

1. The system unit contains essential components like the motherboard, CPU, and storage devices.
2. A plotter is an external device used for printing and is not housed within the system unit.
3. Understanding the roles of different components helps clarify what is included in the system unit.
4. Familiarity with computer hardware terminology is crucial for distinguishing between internal and external components.

Revision Summary

• The system unit houses the motherboard, CPU, and storage devices, but not external peripherals like plotters.
• The plotter is used for printing and operates outside the system unit.
• Recognizing the function and location of computer components is essential for understanding computer architecture.
• Review the definitions and roles of each component to avoid confusion in future questions.