The correct answer is C. Trojan.
A Trojan horse is a type of malware that disguises itself as a legitimate program in order to trick users into installing it on their computers. Once installed, a Trojan can steal personal information, damage files, or even take control of the computer.
A joke program is a type of software that is designed to be funny or entertaining. Joke programs can be harmless, but they can also be malicious. For example, a joke program might play a loud sound or display a message on the screen that is intended to scare or annoy the user.
A worm is a type of malware that can replicate itself and spread from one computer to another without the need for human interaction. Worms can cause damage to files, steal personal information, or even take control of the computer.
A hoax is a false story or rumor that is spread in order to deceive people. Hoaxes can be spread through email, social media, or even word-of-mouth. Hoaxes can cause people to panic or take unnecessary action.
In conclusion, a Trojan horse is a type of malware that disguises itself as a legitimate program in order to trick users into installing it on their computers. Once installed, a Trojan can steal personal information, damage files, or even take control of the computer.