Which type of roof design features a peak or ridge?

The correct choice illustrates that an apex style roof is characterized by its peak or ridge, which is a distinctive feature of this design. An apex roof typically slopes downwards on either side, forming a triangular shape when viewed from the end. This design allows for effective water drainage and can also enhance the structural integrity of the roof.

The peak or ridge not only contributes to aesthetic appeal but also provides additional headroom within the building, which can be beneficial for ventilation and natural light.

Other roof styles, such as flat roofs, do not have a peak and are even across their surface. Barn construction may include ridged roofs but is more specific to agricultural buildings and can vary widely in design. A green roof focuses on vegetation coverage and does not inherently feature a peak or ridge.