Investment has grown in services like banking, IT, call centres, manufacturing: textiles and engineering and entertainment and leisure. It has put pressure on the land in the CBD making it the world's fourth expensive cities!

The question addresses the impact of economic investment on Mumbai, a major urban center in India. Economic investment in various sectors such as banking, information technology (IT), call centers, manufacturing (textiles and engineering), and entertainment and leisure has significantly influenced the city's development. This investment has led to increased economic activity and demand for commercial and residential spaces, particularly in the Central Business District (CBD).

The CBD is the heart of the city where most business activities take place. As economic investment grows, the demand for land in the CBD increases, leading to higher land prices. This phenomenon is not unique to Mumbai but is a common trend in many rapidly developing urban areas around the world. The increased economic activity and investment have made Mumbai one of the most expensive cities globally, as reflected in the high cost of land and real estate.

Understanding the impact of economic investment on urban development is crucial for comprehending the dynamics of urban growth and the challenges associated with it. Economic investment drives urbanization by attracting businesses and people to the city, which in turn increases the demand for infrastructure, housing, and services. This growth can lead to both positive outcomes, such as job creation and economic prosperity, and negative outcomes, such as increased cost of living and pressure on existing infrastructure.

In the context of Mumbai, the growth in various sectors has transformed the city into a major economic hub. However, this transformation has also brought challenges, such as rising land prices, which can make the city less accessible to lower-income residents. The high cost of living in the CBD can lead to issues such as gentrification and displacement of long-term residents, as well as increased pressure on public services and infrastructure.

Therefore, the correct answer is Option C: "What impact has economic investment had on Mumbai?" This option directly addresses the question's focus on the effects of economic investment on the city's development, particularly in terms of land prices and economic activities.