Final answer:
The correct action for a CSIRC plan is notifying relevant authorities promptly to effectively address and manage incidents. Ignoring incidents, disclosing sensitive information publicly, and adopting weak passwords compromises security.
Step-by-step explanation:
Among the options provided, the correct action to be included in a plan element that is part of a Computer Security Incident Response Capability (CSIRC) is Option 2: Notifying relevant authorities promptly. This is because a well-designed CSIRC should emphasize the importance of reporting incidents in a timely manner to ensure that proper measures can be taken to address the incident and minimize damage. Ignoring potential incidents (Option 1), sharing sensitive information publicly (Option 3), and using weak passwords for system access (Option 4) would all be counterintuitive to maintaining strong computer security and could exacerbate the impact of any security incidents.
In creating a CSIRC plan, it's critical to incorporate actions that support emergency preparedness measures, such as anti-terrorism legislation, and ensuring the resilience of critical national infrastructure. This might involve improving individual security measures like implementing two-factor authentication and educating users to avoid scams, as well as enhancing protections on websites for companies and governments.