Which of the following aids in the ability to demonstrate due diligence efforts? Response:

Redundant power lines are a technical control for availability, demonstrating due care for uptime, but not directly for demonstrating security due diligence.

HVAC placement is an environmental control related to physical security and operational continuity, but does not directly demonstrate due diligence in security education or policy adherence.

Security training documentation provides verifiable proof that an organization has implemented measures to educate its employees about security policies, risks, and best practices. This documented effort shows that the organization has acted with reasonable care to prevent security incidents, which is a key aspect of demonstrating due diligence.

Bollards are physical security measures to protect against vehicle attacks, which demonstrate physical due care but not the broader organizational due diligence in security governance or education.