Which of the following describes how the physical features of countries in North America influence trade in these countries?

Most have flat terrain, making railroads the least expensive method of transporting goods.
With oceans on both sides, most countries have access to many sea ports and trade routes.***
Severe temperatures prevent trade between Canada and other countries most of the year.
Physical barriers such as rivers and lakes at their borders make trade difficult.

Right!

The correct answer is: With oceans on both sides, most countries have access to many sea ports and trade routes.

To arrive at this answer, you need to understand the physical features of countries in North America and how they impact trade. Here's an explanation of each option:

1. Most have flat terrain, making railroads the least expensive method of transporting goods.
While this statement is true to some extent, it only addresses the transportation method but not the influence on trade. Flat terrain might make railroads cheaper, but it does not necessarily impact trade significantly.

2. With oceans on both sides, most countries have access to many sea ports and trade routes.
This statement correctly highlights how the physical feature of oceans on both sides of North America influences trade. The presence of oceans provides access to sea ports and trade routes, which facilitates international trade.

3. Severe temperatures prevent trade between Canada and other countries most of the year.
Severe temperatures might affect trade to some extent, but it is too generalized to apply to all North American countries. Additionally, it does not address the influence of physical features directly.

4. Physical barriers such as rivers and lakes at their borders make trade difficult.
While rivers and lakes might pose some challenges to trade in certain areas, it is not a characteristic that applies to all countries in North America. It also does not address the influence of physical features on trade comprehensively.

Therefore, option 2, "With oceans on both sides, most countries have access to many sea ports and trade routes," is the most accurate description of how the physical features of North American countries influence trade.