Answer :
Final answer:
To protect sumps/ejectors from backflow, the use of traps (option b) is essential. Traps prevent the unintended reversal of flow that could introduce contaminants into a system, especially when connected to a vacuum source. Therefore, the correct answer is option b.
Explanation:
The question refers to how sumps/ejectors should be protected to prevent backflow, which is the unintended reversal of the flow of water or mixtures of water and other undesirable substances from any source into the distribution pipes of the drinking water system. The correct option for preventing backflow in this context is b) Traps. Vacuum traps, specifically, are essential when connecting apparatuses to a vacuum source because changes in pressure can cause back-suction. This could result in contaminants being drawn into the vacuum line and flask if not properly mitigated by a trap. For example, when using a water aspirator, this back-suction could pull water from the sink into the vacuum line, contaminating the system. Therefore, using traps is crucial for maintaining the purity of substances in these systems by safeguarding against backflow. Therefore, the correct answer is option b.