What is the elevation of the waste line located below the sub-basement floor?

In this scenario, the elevation of the waste line is indicated as being below the sub-basement floor, which is typically measured in negative values relative to a reference point, commonly the finished floor level. The correct answer of -2 feet and 0 inches means that the waste line is positioned 2 feet below the reference point of the sub-basement floor.

This specific value suggests that the waste line is situated at a level that is relatively shallow compared to typical installations where waste lines can sometimes be found deeper for various reasons such as drainage needs or structural considerations. It's important to ensure that waste lines are installed at the correct elevation to maintain proper flow and prevent any potential clogs or backflows.

Options that indicate deeper elevations, such as -3 feet 3 inches, -4 feet 6 inches, and -5 feet 0 inches, suggest deeper placements that may not be necessary or practical depending on the design of the plumbing system and the overall configuration of the sub-basement, which can lead to additional construction challenges and costs. Thus, the selected elevation of -2 feet is both practical and suitable for effective waste management in relation to the sub-basement floor.