Answer:
The most appropriate answer is C. At least 3.
Step-by-step explanation:
Each state in the United States of America owns its 811 call center to people with anything that involves digging.
When somebody calls 811, it automatically routes them directly to that very call center in their area within the United States.
Then, a 811 representative takes information about the project and assigns the appropriate company so one should contact 811 at least 3 days before beginning the work.