A long building drain changes direction several times behind permanent construction. What service provisions should the estimator include?

Why B is correct

The best answer is: Required accessible cleanouts at applicable locations. Drainage systems need accessible maintenance points; traps and vent devices do not provide mechanical cleaning access. The best answer is therefore “Required accessible cleanouts at applicable locations.” The other choices either address a different system, rely on an unsafe shortcut, or make a conclusion not supported by the stated facts. The transferred field condition applies the same plumbing design, installation, service, or safety principle to a different project setting. The alternatives omit a prerequisite, conflict with the approved method, or fail to control the stated sanitation or physical hazard.