Which of the following is a technique to respond to an insider threat?

Selecting "all of these choices" is correct because it encompasses a comprehensive approach to managing insider threats. Insider threats can originate from employees or other trusted individuals who exploit their privileges to access sensitive information or cause harm to the organization.

Blocking malicious user accounts serves as an immediate response to prevent an individual from continuing harmful activities. This is crucial because swift action can limit the potential damage caused by the insider.

Disabling system access for malicious users further secures the environment by ensuring that individuals who pose a risk cannot access critical systems, data, or resources. This can help prevent any further unauthorized access or data breaches that may arise from their continuing access.

Placing malicious users in a quarantine network can be an effective containment strategy. This approach isolates the user from sensitive systems while still allowing the security team to monitor their actions and gather intelligence on their behavior, which could be essential for mitigating future risks.

Combining all these techniques provides a multifaceted response to insider threats, effectively securing the organization from various angles and ensuring thorough risk management.