What is the primary difference between a virus and a worm?

Correct answer: Viruses require user action to spread; worms spread automatically without user interaction

Option C is correct because a virus is malicious code that requires a host file and typically needs a user to execute it or open an infected file for the code to activate and propagate, whereas a worm is self-contained malware that exploits vulnerabilities to replicate and spread across networks automatically without any user interaction. Option A is incorrect because viruses and worms are meaningfully distinct in their propagation mechanisms and do not refer to the same thing. Option B is incorrect because destructiveness is not the defining difference; a worm may or may not be more destructive than a virus depending on its payload, and the key distinction is the propagation method. Option D is incorrect because both viruses and worms have existed for decades; neither is newer technology than the other, and age is not a meaningful differentiator between the two.