Anti-virus software:

**The reasoning** Anti-virus software is a protective program designed specifically to guard your computer against malicious software (malware) — including viruses, worms, trojans, and spyware. Think of it like a security guard at a gate: it scans files coming into your system, compares them against a database of known threats, and either blocks harmful programs or removes them if they've already infected your device. The core principle is **cybersecurity protection** — keeping your data and system safe from harm. **Why the wrong options tempt you** **A** is the opposite — anti-virus *fights* viruses, not spreads them! **C** might confuse you because some security software bundles optimization tools, but speeding up internet isn't the anti-virus's main job. **D** sounds tech-related but confuses anti-virus with graphics software like Photoshop or CorelDRAW — completely different purposes. **Quick takeaway** Anti-virus = Anti (against) + Virus — it's your computer's immune system that detects threats and removes them, nothing else. Remember: protection is its only mission!