Concept:Antivirus software is a security tool that detects, blocks, and removes viruses before they can damage a computer.
Explanation:Installing an antivirus program creates a protective layer that continuously scans files, downloads, and running programs for threats.
Updating the antivirus regularly is essential because new viruses appear daily.
Updated virus definitions help the software recognise and stop the latest forms of malware.
Enabling automatic updates ensures the computer stays protected against newly discovered viruses.
Other options, such as reinstalling the operating system, purchasing a new computer, or using external disks on public computers, do not directly prevent virus effects.
These methods may remove or avoid an existing infection, but they do not provide ongoing protection against viruses.
Therefore, the most reliable way to prevent virus effects is to combine antivirus installation with regular updates.
Answer:A. installing and updating antivirus