Specify the characteristics of the enclosed mezzanine that is not considered a storey.
a) It must not exceed one-third of the area of the room or space in which it is located.
b) It must be open on at least one side with an opening that is not less than one-third of the perimeter of the mezzanine.
c) It must be used solely for the purposes of service and maintenance of the building.
d) It must not contain a grouping of upholstered furniture.