Which of the following indicates a safety chain should be checked?

The correct choice focuses on the importance of rubber seals being intact, which is crucial for ensuring a proper and secure connection in towing scenarios. Safety chains are designed to secure the trailer to the towing vehicle in case the primary attachment fails. The integrity of the rubber seals contributes to the overall reliability of the connection points, preventing disconnection that could lead to accidents.

When rubber seals are intact, they help maintain a tight fit and reduce the risk of wear or debris entering the connection area, which could compromise safety. Ensuring that these seals are in good condition is a standard safety practice during a pre-trip inspection to protect both the driver and other road users.

In contrast, the other choices do not relate to standard safety checks for chains. For example, indicating that a safety chain must be cracked or bent suggests a failure of the component, while stating that safety is not a concern directly contradicts the fundamental principles of safe driving and vehicle operation.