Final answer:
The correct option is 1. For building sewers 8 inches or larger, the permitted minimum slope with proper approval is 1/8 inch per foot, essential for efficient waste flow and preventing blockages.
Step-by-step explanation:
The correct slope for building sewers 8 inches or larger, with the appropriate cause and Authority Having Jurisdiction approval, is 1/8 inch per foot. When designing and installing sewer systems, ensuring the appropriate slope is critical for the flow of sewage and wastewater.
The slope ensures that waste moves efficiently through the sewer system without creating blockages or requiring excessive maintenance. While there might be small regional variations depending on local codes or the specific Authority Having Jurisdiction, the general guideline is as specified.