Based on the following passage, why might an architect choose to use a curtain wall? Office buildings and high-rises often include a curtain wall of glass, which requires advanced systems of fastening glass plates together. In a building with a curtain wall, the covering of the building does not serve a structural purpose; it is simply a façade that keeps out the elements. A curtain wall can be made of a number of different materials, such as aluminum, stone veneer, or glass.

It can be easily removed and frequently changed.

It is effective at resisting all types of weather including hurricanes and earthquakes.

It can reinforce the structural integrity of the building.

It can be made of lightweight, inexpensive materials.