Final answer:
The desktop computer has a system unit that is easily distinguished from the peripherals. Hence the correct answer is option 3
Step-by-step explanation:
The computer that has a system unit that is easily distinguished from the peripherals is the desktop computer.
In a desktop computer, the system unit is often a separate tower or box that houses the main components of the computer, such as the motherboard, processor, and memory. The peripherals, on the other hand, are devices that connect to the computer, such as the monitor, keyboard, and mouse.
In contrast, devices like smartphones, handhelds, and laptops have their system units integrated within the same casing as the peripherals, making it more difficult to distinguish them.
Hence the correct answer is option 3