What is a computer virus?

• A. A form of harmless software
• B. A program that enhances system performance
• C. Malicious software that replicates itself
• D. A tool used for web browsing

Answer: (C)

A computer virus is classified as malicious software designed to replicate itself and spread from one computer to another. Once this software infiltrates a system, it can disrupt normal operations, steal information, corrupt files, or cause other forms of harm. The replication aspect is what distinguishes it from benign software; as a virus spreads, it can infect additional files and systems, often without the user's knowledge or consent.

The other options presented do not accurately describe a computer virus. Harmless software does not have harmful intentions or actions. A program that enhances system performance implies positive functionality rather than any form of malicious intent. Lastly, a tool used for web browsing pertains to software designed for navigating the internet and does not have any relation to the attributes or actions of a computer virus. Thus, the defining characteristic of a virus as a self-replicating malicious software distinguishes it distinctly from these other concepts.