a cross connection is a link between

A cross-connection is a link between:

A. the public water supply and the operation.
B. safe and contaminated water.
C. plumbing and ventilation pipes.
D. air ducts and heating vents.

A cross-connection occurs when there is a direct link between potable (safe) water and non-potable (contaminated) water. This condition can result in the backflow of contaminants into the clean water supply, posing serious health risks. Understanding what constitutes a cross-connection is essential for preventing water contamination and ensuring the safety of the public water system.

Explanation:
Cross-connections are hazardous because they allow contaminants, chemicals, or pollutants to enter the clean water supply through backflow. This typically happens when there is a drop in water pressure, allowing non-potable water to flow in the opposite direction. To prevent these risks, regular inspections and proper plumbing systems are necessary. The key to avoiding cross-connections is maintaining a separation between potable and non-potable water systems.

Answer:
The correct answer is:
B. safe and contaminated water.