What system is designed to prevent unauthorized data transmission?

Data Loss Prevention (DLP) systems are specifically designed to monitor, detect, and secure sensitive information from being sent outside of a designated network or environment. These systems apply various policies and rules to ensure that data is not transmitted or disclosed without proper authorization, thus preventing data breaches and leaks. DLP technologies can analyze data in use, data in motion, and data at rest, ensuring that critical information remains secure.

In contrast, while a firewall can control access to a network and block certain types of traffic based on pre-defined security rules, its primary function is not to prevent the transmission of sensitive data; instead, it's more about filtering and controlling overall traffic flow. Similarly, encryption software aims to protect data by making it unreadable without proper decryption keys, but does not necessarily prevent unauthorized transmission; it merely secures the data during transmission. Antivirus programs focus on detecting and removing malicious software rather than specifically managing or controlling data transmission. Hence, DLP is uniquely suited for the task of preventing unauthorized data transmission.