Glass doors enclosing the shower must be made of what type of glazing?

The correct choice is safety glazing. Glass doors enclosing a shower are required to be made from materials that provide a level of protection against breakage due to impact or thermal stress. Safety glazing typically refers to toughened or laminated glass, designed to shatter into small, less dangerous pieces rather than sharp shards, which can help prevent injuries in the event of accidental breakage.

While tempered glass is a common form of safety glazing, the term "safety glazing" encompasses a broader category that includes materials specifically regulated for use in areas where there is a risk of glass breakage in wet environments, such as bathrooms. This ensures that not only is the glass strong and resilient but also complies with safety codes that protect individuals using the shower.

The other options, like clear glass, frosted glass, and tempered glass, might partially meet requirements but do not encapsulate the broader safety standards that the term "safety glazing" conveys, which is crucial for ensuring safety in residential and commercial buildings.