Which of the following is a critical metric for measuring incident response effectiveness?

Mean time to detect (MTTD) is a crucial metric for evaluating the effectiveness of incident response because it directly reflects the organization's ability to identify security breaches or incidents in a timely manner. A lower MTTD indicates that an organization can recognize threats quickly, which is essential for minimizing damage and recovering from incidents more efficiently.

Prompt detection allows for faster response actions, potentially mitigating the impact of an ongoing attack. Effective incident response hinges on being able to spot incidents early on so that appropriate procedures can be initiated to contain and remediate the threat.

In comparison, while the rate of software updates and the percentage of user logins can inform broader security postures, they don't directly measure the effectiveness of incident response. The cost of cybersecurity insurance indicates a financial approach to risk management but also doesn't relate to how efficiently an organization can respond to incidents when they occur. Thus, MTTD stands out as the most relevant metric for assessing how well an organization manages its incident response processes.