Step 1: Understanding Urbanization and Its Problems:
Urbanization is the process of population shift from rural to urban areas, leading to the growth of cities. This rapid growth often leads to several socio-economic and environmental challenges. Common problems include housing shortages, development of slums, traffic congestion, pollution, and strain on public services.
Step 2: Analyzing the Options:
- (A) Extensive agriculture: This refers to a farming system that uses large areas of land with low inputs of labor and capital. Urbanization is characterized by the conversion of agricultural land into residential, commercial, and industrial areas. Therefore, extensive agriculture is contrary to the process of urbanization and is not a problem caused by it. In fact, urbanization leads to a \textit{reduction} in agricultural land.
- (B) Slum area: The rapid influx of people into cities often outpaces the availability of affordable housing, leading to the formation and growth of slums, which are a major problem of urbanization.
- (C) Traffic problems: Increased population and vehicle ownership in cities lead to traffic congestion, which is a classic problem of urbanization.
- (D) Industrialization: While industrialization is a major \textit{cause} or driver of urbanization, the associated effects like industrial pollution are significant problems within urban areas. In the context of "problems of urbanization," industrialization itself can be viewed as a source of problems. However, compared to extensive agriculture, it is directly linked to the urban process.
Step 3: Final Answer:
Extensive agriculture is not a problem of urbanization; rather, it is a land use that is displaced by urban growth. The other options are either direct problems (slums, traffic) or closely associated causes/problems (industrialization). Therefore, extensive agriculture is the correct answer.