What are the available maximum heights for high pressure air bags?

The available maximum heights for high-pressure air bags are indeed 6, 9, 14.5, and 15.5 inches. These measurements are significant as they correspond to the range of sizes typically used in various applications involving high-pressure air systems, especially in lifting and transportation scenarios.

The selected heights provide flexibility in operation, allowing users to choose the appropriate size based on the lifting requirement and the design specifications of the task at hand. The specific increments also reflect common engineering standards and typical applications where these air bags are utilized for safe lifting and support under heavy loads.

Other options present different heights that do not align with the standard sizes utilized in industry. Thus, option B is the correct choice as it accurately represents the recognized maximum heights for high-pressure air bags.