Which method of transit has had the biggest impact on world trade in the twenty-first century?
orailroads
canals
steam boats
container ships

the correct answer is D. container ships

The best method of transit for world trade is the container ships

Explanation:

There are ports and waterways in almost all parts of the world. container ships carry a very large amount of goods across the waterways and ports connecting several parts of the world while other means of transport are limited in one way of the other for example railroads and canals don't connect  or link most parts of the world while steam boats can carry a limited number of goods and services if they do and they can't travel safely on very large oceans and seas