Final answer:
The Panama and Suez Canals significantly impacted the global economy and reduced the cost of transporting goods, making options a) and c) the correct results of their construction. The correct option is d.
Step-by-step explanation:
The construction of the Panama Canal and the Suez Canal had a significant impact on the global economy by revolutionizing maritime trade routes. By creating direct routes between the Atlantic and Pacific Oceans, the Panama Canal in particular became an essential transportation link for both the United States and the wider world, dramatically reducing the cost of transporting goods.
Consequently, this reduced travel time for shipping routes which in turn lowered transportation costs, helping to foster globalization and economic growth.
Answering the student's question, the results of the Panama and Suez canals were a) an impact on the global economy, and c) reduced cost of transport of goods. Hence the correct choice is d) A & C only. These canals did not have the goal of reducing carbon emissions, so b) is not accurate.