Efforts to develop infrastructure in Assam are crucial for economic growth as they:

Reduce transportation costs
Facilitate trade
Attract investment
All of the above

The correct answer is: d) All of the above

Infrastructure is the basic physical and organizational structures and facilities needed for the operation of a society or enterprise, such as roads, bridges, buildings, airports, dams, power plants, and railways. It is essential for economic growth as it provides the foundation for businesses to operate and for people to live and work.

Infrastructure can reduce transportation costs by making it easier and cheaper to move goods and people around. This can lead to lower prices for consumers and businesses, and can make it easier for businesses to reach new markets.

Infrastructure can also facilitate trade by making it easier to move goods across borders. This can lead to increased trade and economic growth.

Finally, infrastructure can attract investment by making it a more attractive place to do business. This can lead to new jobs and economic growth.

In conclusion, efforts to develop infrastructure in Assam are crucial for economic growth as they can reduce transportation costs, facilitate trade, and attract investment.