Which of the following is a valid reason for frustrating cargo?

Frustrating cargo refers to the process of temporarily holding cargo that cannot be delivered or processed for various legitimate reasons. A request by the Air Cargo Authority or Cargo Service Branch to hold cargo is a valid reason because these authorities may determine that specific circumstances require cargo to be held to ensure safety, security, or compliance with regulations. This can include reasons such as missing documentation, discrepancies in cargo information, or changes in operational priorities.

In contrast, while weather-related delays, inadequate shipping supplies, and company policy changes may pose challenges, they do not necessarily constitute valid reasons for frustrating cargo in the same regulatory or operational context. They often relate more to logistics or operational issues rather than formal directives that necessitate holding cargo, which is why the request from authorities stands out as the correct answer.