The correct answer is the unintended consequences of social change
Social change is the transformation of society and its way of organization. It stems from habits and customs that they stop doing or that start to be part of people's daily lives.
Abolition of slavery, rural exodus and evolution of means of transport are just a few examples of events that have transformed society. Therefore, they are occurrences of social changes.
For Canadian sociologist Guy Rocher (1924), social change must be observed under the historical current. Social change is not temporary, it is constant and affects the development of society.