the counties are Macomb county and Wayne county.
Macomb County and Wayne County are the two local governmnet organization which can operate under a home rule charter type of government, and both have chosen the county executive form government. when a county or city is incoroprated it can change its charter or rules internally without the hands of the state.
As they had no correct method of communicating
I believe the answer is C, immunity because (immunity) means protection or exemption from somethings, especially an obligation or penalty. So the key word in the question is protection. I hope this helps and just stating I am NOT 100% sure.
because they used them for jobs and relied on them to operate