Answer:
oldest and most commonly used form of city government ( D )
Step-by-step explanation:
The Mayor-council system of city government is one of the oldest and most commonly used form of city government used in the United states of America and Canada, it is comprised of an elected Mayor and an elected legislative city council and it is more applicable in large cities.
It is like a replica of what happens at the state level. where there is an elected Governor and an elected Legislature. The Mayor appoints a city-administrator who oversees the daily running of city affairs.