What safety feature must be provided near roof hatch openings that are close to a walking surface?

The correct choice is guards. Guards are essential safety features that help prevent accidental falls or injuries when working near roof hatch openings that are near a walking surface. These guards act as a physical barrier, providing protection by either enclosing the opening or preventing unaided access to the edge, ensuring that workers are safeguarded from potential hazards associated with the hatch.

While railings, barriers, and signs can also contribute to safety, they serve different purposes. Railings typically surround areas to offer support and enhance overall safety, but they may not be specifically designed for preventing falls at hatch openings. Barriers might be more effective in controlling access to certain areas but might not provide the same level of protection as guards. Signs serve the important role of alerting individuals to hazards, but they do not physically prevent accidents. Guards are specifically designed for this application, making them the most appropriate safety feature in this context.