Which of the following is NOT one of the basic components of door construction?

The basic components of door construction include the door itself, the jamb, and the hardware. The door is the main component that swings or slides to allow entry or exit, while the jamb is the vertical part of a frame that holds the door in place. Hardware refers to the mechanisms used to operate the door, such as hinges, locks, and handles.

The sill, while important in certain contexts such as window construction or design for water drainage, is not considered a fundamental component of door construction. Therefore, the answer indicates an understanding that the primary elements involved directly in the structure and function of a door do not typically incorporate a sill as one of their basics. This delineation is crucial for understanding architectural and construction principles in relation to doors.