Which component is typically labeled as 'D' in a balustrade assembly?

In the context of a balustrade assembly, the component typically identified as 'D' is the handrail. The handrail serves a crucial function by providing support and stability for individuals when ascending or descending stairs or navigating along a balcony or elevated walkway. Handrails are designed to be graspable and are an essential safety feature that helps prevent falls.

The handrail is often placed at a height that is comfortable and accessible for users. It may come in various designs and materials, allowing it to blend aesthetically with the surrounding architecture while still maintaining its primary functional role.

Other components of a balustrade include the balusters, which are the vertical posts that support the handrail and provide the necessary spacing and safety; the newel, which is a large post at the start or end of a railing or at a turn in the staircase; and the nosing, which refers to the edge of the stair tread that extends beyond the riser. Each part plays a specific role within the assembly, but when identifying the component labeled as 'D', the handrail is the correct choice.