What is a Trojan Horse in the context of computing?

A Trojan Horse in computing refers specifically to a type of malicious software that appears to be harmless or beneficial to the user but is designed to perform harmful actions once executed. This aligns with the concept of option B, as a Trojan Horse can be programmed to unleash a virus or other types of malware at a predetermined time or under certain conditions, thereby compromising the user's system without their knowledge.

The definition stems from the well-known historical tale in which Greek soldiers hid inside a large wooden horse to infiltrate the city of Troy, leading to its downfall. In the digital context, users are often tricked into downloading or running such a program because it mimics the appearance of legitimate software or files. Once activated, it executes its malicious intent, which could include data theft, system damage, or unauthorized access to sensitive information.

Understanding this concept is crucial, as it highlights the importance of vigilance when downloading and installing software, as well as the need for effective cybersecurity measures to detect and prevent such threats.