Which of the following best describes a "metropolitan area"?

A metropolitan area is best described as an urban region that typically encompasses a large city along with its surrounding communities, often defined by socioeconomic ties, infrastructure, and commuting patterns. The characteristic of having at least one city with a population of 100,000 is significant because it indicates a central urban hub that drives the economy and culture of the region. This threshold helps to classify the area as metropolitan rather than rural or suburban.

In contrast, the other definitions provided do not adequately represent a metropolitan area. Regions comprising only rural areas lack the urban characteristics that define metropolitan areas. An area with no municipalities fails to meet the criteria for urban classification, as metropolitan areas are defined by their urban centers. Similarly, limiting the area to only industrial zones ignores the broader social and residential components that are integral to the definition of a metropolitan area. Thus, option A effectively captures the essence of what constitutes a metropolitan area.