Security awareness training is a process of educating and informing the users about the security policies, procedures, and best practices of the organization, and the potential threats and risks that may affect the confidentiality, integrity, and availability of the information and systems.

The best indicator of whether security awareness training is effective is user behavior after training. This means that the users demonstrate and apply the knowledge and skills that they have learned from the training, such as following the security rules and guidelines, reporting any security incidents or issues, avoiding any risky or malicious actions, etc.

User behavior after training helps to measure the actual impact and outcome of the training, compare them with the expected or desired objectives and standards, identify any gaps or issuesthat may affect the training effectiveness or efficiency, and take appropriate actions to address them.

The other options are not the best indicators of whether security awareness training is effective. They are either subjective or not essential for security awareness training.

The references for this answer are:

Risk IT Framework, page 30

Information Technology & Security, page 24

Risk Scenarios Starter Pack, page 22