Endpoint logs provide invaluable information regarding the activities occurring on individual systems. In this case, repeated login failures followed by a successful login often indicate a brute force attack, where an attacker has repeatedly attempted to log in using different passwords until the correct one is found. This is a common indication of a compromised account, which is why the answer detailing this pattern is correct. The other answers describe events that may be ordinary and not indicative of a security incident, such as a single successful login, periodic security scanning, or regular system updates.