Which of the following is a typical type of glazing system used in commercial buildings?

A typical type of glazing system used in commercial buildings is the curtain wall. Curtain walls are non-structural exterior walls that are designed to allow for a large amount of glass to be incorporated into the facade of a building. This allows for natural lighting, which can enhance the aesthetic appeal of the structure and contribute to energy efficiency by reducing the need for artificial lighting during the day.

Curtain walls are usually made of lightweight materials, such as aluminum frames with glass panes, which makes them suitable for high-rise buildings where minimizing weight is crucial. They do not carry any structural load from the building except their own weight and wind loads, thus allowing for flexible design choices in the overall architecture of the building.

Other options like foundation walls, roof trusses, and load-bearing walls serve very different functions in the structure of a building. Foundation walls provide stability and support to the building, roof trusses are components that support the roof, and load-bearing walls are integral to the building's structural integrity. These options do not incorporate glazing systems in the same way that curtain walls do.