Emily, a member of the cybersecurity response team, receives an alert indicating suspicious login attempts...

Comprehensive and Detailed Explanation (ECIH-aligned):

The ECIH incident validation phase emphasizes the importance of direct evidence when confirming unauthorized access. Log entries that show access to sensitive or restricted files provide concrete proof that an attacker successfully breached controls.

Option B is correct because access logs tied to critical resources confirm both authentication success and unauthorized activity. Failed logins or system performance issues alone do not confirm compromise.

Option A, C, and D are indirect indicators that may signal suspicious behavior but cannot independently confirm unauthorized access.

Therefore, verified log evidence is the strongest indicator, aligning with ECIH incident triage and validation principles.