Which statement is TRUE about buoys marked with reflective material?

The statement about preferred-channel buoys indicates that these markers have reflective material that corresponds with their navigating purpose. Specifically, a preferred-channel buoy will display reflective material in red or green colors, matching the color of the top band. This is critical for providing nighttime visibility and aiding navigation in low-light conditions. The colors red and green are essential for visually indicating the best channel for vessels to traverse safely, further ensuring compliance with the IALA (International Association of Lighthouse Authorities) buoyage system.

In contrast, while other statements may contain aspects of truth, they do not correctly describe the characteristics of buoys as specified in the Aids to Navigation system. For instance, a safe-water buoy does feature reflective materials, but it's characterized by vertical red and white stripes rather than specifically focusing on the reflective aspect. The notion that all reflective material is white ignores the necessity of color-coded navigation aids designed specifically for safe maritime navigation. Although special-purpose marks are indeed significant, their designation doesn’t strictly enforce that the reflective material must adhere to red or green without proper context. Thus, the specificity of the preferred-channel buoy’s descriptive features solidifies the correctness of that statement.