Concept:Antivirus software is designed to detect, prevent, and remove malicious software like viruses, worms, and trojans.Explanation:Among the given options, Norton is a well-known antivirus product developed by Norton LifeLock. It uses signatures and heuristics to identify threats and provides real-time protection. Photoshop is an image editing tool. Yahoo is a web services provider. Flash is multimedia software for animations. Only Norton fits the definition of antivirus software.Answer:B. Norton