Which of the following is an attack in which multiple systems flood the bandwidth?

The correct answer identifies a DDoS (Distributed Denial of Service) attack, which is characterized by multiple compromised systems being used to flood the bandwidth of a targeted system. In a DDoS attack, attackers control a network of machines, often infected with malware, and orchestrate them to send a high volume of traffic to a single target. This overwhelming flood of requests can cause the target server or network to slow down or become completely unresponsive, leading to denial of service for legitimate users.

DDoS attacks exploit the sheer volume of traffic that can be generated from numerous machines, making them particularly difficult to defend against due to their distributed nature. The scale at which these attacks can occur is a significant factor, as they rely on multiple sources to amplify their impact, which distinguishes them from other types of attacks that focus on exploiting software vulnerabilities or directly targeting specific data. In contrast, the other options pertain to different types of attacks — brute-force attacks aim to gain access through repeated attempts at guessing passwords, SQL injection targets databases through malformed queries, and cross-site scripting (XSS) involves injecting malicious scripts into web pages viewed by others. Each of these methods has different objectives and mechanisms that do not involve flooding bandwidth in the same manner as