What best describes preventive controls?

Preventive controls are specifically designed to avert security incidents before they can occur. These controls serve as the first line of defense in an organization's security strategy, implementing measures that can mitigate risks and reduce vulnerabilities. For example, preventive controls may include firewalls, antivirus software, access controls, and security training for employees. By focusing on the prevention of incidents, these controls help maintain the confidentiality, integrity, and availability of information systems, creating a proactive approach to security.

In contrast, the other options refer to different types of controls that do not fit the definition of preventive measures. For instance, controls that identify breaches after they occur are more aligned with detective controls, which aim to discover security issues once they have manifested. Sharing information with stakeholders pertains to communication or management controls rather than prevention, while auditing systems focuses on review and compliance, falling under the category of corrective controls that help ensure proper governance rather than preventing incidents outright.