According to the theory of comparative advantage, consumers in all nations can consume more if there are

no restrictions on trade

Explanation:

Comparative advantage in economics is the ability of an individual or country to produce a specific good or service at a lower opportunity cost better than another individual or country.

The comparative advantage gives a country a stronger sales margin than their competitors as they are able to sell their specific products or render their peculiar services at a lower opportunity cost.

In 1817, David Ricardo who is an english political economist talked about the law of comparative advantage in his book “On the Principles of Political Economy and Taxation." where he asserted that countries can become better off by specializing in what they do or produce best and eliminate trade barriers (restrictions).

This simply means that, any country applying the principle of comparative advantage, would enjoy an increase in output and consequently, a boost in their Gross Domestic Products (GDP).

Hence, according to the theory of comparative advantage, consumers in all nations can consume more if there are no restrictions on trade.