Explanation:

Peripheral equipment refers to any external device that connects to a computer system and adds functionality but is not part of the core computer architecture (CPU, memory, motherboard). These devices can be input devices (like keyboards, mice, scanners), output devices (like printers, monitors, speakers), or storage devices (like external hard drives, USB drives). Option (b) 'large-scale computer systems' describes a type of computer, not attached devices. Option (c) 'a program collection' refers to software, not hardware. Option (d) 'other office equipment not associated with a desktop computer' is too vague and incorrectly excludes devices *associated* with a desktop computer. The most accurate and comprehensive definition is 'any device that is attached to a computer system' to enhance its capabilities.