Final answer:
Open sided walking or raised floor surfaces located more than 30 inches above the ground should have guards that are at least 42 inches high to ensure safety and prevent falls.
Step-by-step explanation:
The question is related to safety requirements for raised surfaces such as platforms or walkways in respect to the guards or railings that are to be installed to prevent falls. According to the International Building Code (IBC) or the Occupational Safety and Health Administration (OSHA) standards, open sided walking or raised floor surfaces located more than 30 inches above the floor or grade below, shall have guards not less than 42 inches in height. These parameters are set to provide a minimum level of safety and to prevent accidental falls from elevated surfaces.