What is the purpose of a Denial of Service Attack?

The purpose of a Denial of Service (DoS) attack is to flood a server with an overwhelming amount of traffic, rendering it unable to respond to legitimate requests or causing it to crash. This malicious act is typically executed by sending numerous requests to the server, which consumes its resources such as CPU, memory, and bandwidth. As a result, genuine users experience a denial of service, meaning they are unable to access the website or online services that rely on that server.

The other options do not align with the characteristics of a DoS attack. Enhancing server performance or improving website accessibility would involve legitimate optimization and maintenance efforts, which are contrary to the disruptive nature of a DoS attack. Similarly, while protection against unauthorized access is crucial, it does not relate to the intention behind a Denial of Service attack, which is purely to disrupt service rather than to protect it. Therefore, option B correctly encapsulates the main objective of a DoS attack.