Read a passage about urbanization in Vietnam and mark the letter A, B, C, or D on your answer sheet to indicate the best fits each of the number blanks.

Urbanization in Vietnam: Opportunities and Challenges
Urbanization is transforming Vietnam at an incredible speed. Over the past 30 years, ___(1)___, attracting millions of people from rural areas. Today, about 40% of Vietnam's population lives in urban areas, compared to just 20% in the 1980s.
The main reason for this shift is economic opportunity. Cities offer better jobs in factories, offices, and the growing service sector. For many, moving to the city means a chance for a better life, with higher salaries and access to modern facilities. Urban areas also play a key role in Vietnam’s economy, ___(2)___.
However, urbanization has also brought challenges. Housing shortages, traffic jams, and air pollution are common in major cities. Public services like schools, hospitals, and transportation systems often struggle to keep up with the growing population. ___(3)___, where living conditions are poor.
To address these issues, Vietnam is investing in better urban planning and infrastructure. Projects like smart cities and eco-friendly developments aim ___(4)___.
Urbanization has given millions of Vietnamese people new opportunities, ___(5)___.
(Adapted from https://www.statista.com/statistics/444882/urbanization-in-vietnam/)