Roofs having a span of 40 feet or less and a pitch of ? or greater are considered to be pitched.

Roofs with a span of 40 feet or less and a pitch of 1/4 or greater are classified as pitched roofs. The term "pitch" in roofing refers to the steepness or slope of the roof. A pitch of 1/4 means that for every 4 horizontal units, the roof rises vertically by 1 unit. This degree of slope is significant enough to facilitate water drainage and can also influence the type of roofing materials used, as well as the design of any lightning protection systems that might be implemented.

Pitched roofs also have structural benefits, as they can help to minimize the accumulation of debris and snow, thus reducing the risk of damage due to weight or moisture. In the context of lightning protection, recognizing pitched roofs is important because these structures may require specific considerations in their lightning protection designs given their height and exposure to lightning strikes.

Other options presented convey different pitches that do not meet the minimum requirement for being classified as pitched. Therefore, the choice of 1/4 provides the correct standard for identifying pitched roofs within the specified spans.