Which description matches a worm?

• A. A program capable of reproducing itself that can spread to other computers over a network
• B. A patch for fixing security vulnerabilities
• C. A device driver for peripherals
• D. A spell-checker tool

Answer: (A)

A worm is a self-replicating program that can spread to other computers over a network by reproducing itself and moving from one system to another, often by taking advantage of security vulnerabilities. That automatic propagation across machines is what makes it fit this description. In contrast, a patch fixes security holes, a device driver enables hardware communication, and a spell-checker is a language tool. So the description matches how a worm operates: autonomous propagation through networks.