Problems that prevent filling a cylinder include: Cracks or leaks; Out-of-date requalification; Bulging, denting, or gouging. Which option completes the list?

• A. Cracks or leaks
• B. Out-of-date requalification
• C. Bulging, denting, or gouging
• D. All of the above

Answer: (D)

The main idea is safety: a cylinder must be in proper condition and properly certified to be filled. Cracks or leaks breach the pressure boundary, posing a real risk of gas escape and possible ignition. If the cylinder’s requalification is out of date, its structural integrity hasn’t been confirmed within the required interval, so filling would be unsafe. Bulging, denting, or gouging signals damage that weakens the wall and can fail under pressure. Since any one of these problems makes filling unsafe, the option that includes all of them is the correct choice.