What solution allows emails to remain in the deleted folder for a specified duration and prevents individual users from changing settings?

The correct answer is the Email Retention Policy. This solution is specifically designed to manage how long emails are retained in a deleted folder, ensuring that they remain there for a specified duration before being permanently deleted. This policy is essential for organizations that need to comply with regulatory requirements or internal governance around data retention.

An Email Retention Policy can prevent individual users from changing settings related to email retention, as these policies are typically enforced at the organizational level. This means that whether emails can be restored or when they are permanently deleted is controlled centrally, providing the organization with better oversight and management of email data.

In contrast, a File Plan generally pertains to the classification and management of documents rather than emails specifically. Data Loss Prevention focuses on preventing sensitive data from being shared outside the organization, and Access Control Setting relates to user permissions and access to data, which does not specifically address email retention strategies. These alternatives do not provide the same level of control over email retention as an Email Retention Policy does.