The correct answer is 'Directly from the antivirus software's update feature', because it ensures you are getting the legitimate and most recent updates provided by the software's developer. Updates through this method are typically vetted and secure. Downloading from an email link can be risky because attackers often use phishing emails that mimic legitimate sources to spread malware. Manufacturer's forums, while potentially useful for support, are not official channels for software updates and may expose you to unverified uploads. Third-party app stores may offer outdated or modified versions of the software that can be harmful or not function as intended.