A 4-inch diameter horizontal drainage pipe is installed with a slope of 1/8 inch per foot. According to the 2022 CPC, is this installation acceptable for a building drain?

• No, because 4-inch pipe requires a minimum slope of 1/2 inch per foot.
• Yes, because 4-inch pipe requires a minimum slope of 1/8 inch per foot.
• No, because all horizontal drainage piping requires a minimum slope of 1/4 inch per foot.
• Yes, but only if it is a building sewer, not a building drain.