1. A
2. I don't know
3. C
4. I don't know
5. I don't know
Answer:
Create an air gap to prevent backflow.
Explanation:
An air gap prevents contamination of the water because it creates a space between the water outlet and a contaminated source. So, if there is, for example, a decrease in the pressure that pumps the water to the faucet, the water the air gap will prevent the contamination of potable water and the cause of different illnesses.
