Read the following passage about endangered languages and mark the letter A, B, C or D on your answer sheet to indicate the best answer to each of the following questions from 23 to 30.

In recent years, the concept of “smart cities” has gained traction worldwide. Smart cities integrate technology to enhance the quality of life for citizens, streamline operations, and manage resources efficiently. Cities like Singapore and Barcelona have embraced this approach, utilizing sensors and data analytics to monitor traffic, control energy consumption, and improve public services.

One crucial aspect of smart cities is the development of eco-friendly infrastructure. By using sustainable materials and optimizing energy use, cities reduce their environmental footprint. In Tokyo, for example, new buildings are required to meet strict environmental standards, and urban farms are being established on rooftops to improve air quality and provide fresh produce locally.

Despite the many benefits, smart cities face challenges. Privacy concerns arise as those cities collect extensive data to support their systems. Furthermore, the high costs associated with implementing smart technology can strain municipal budgets. However, governments and private entities are collaborating to find cost-effective solutions.

In conclusion, smart cities offer a vision of the future where technology and sustainability are combined. While obstacles remain, the continuous development of smart infrastructure holds promise for urban life across the globe.

(Adapted from 465.IT)

Which of the following best paraphrases the sentence in paragraph 4?