Q. Which among the following is primary reason for trade among countries?
Answer: the existence of price differentials among nations
Notes: The primary reason for trade among countries is the existence of price differentials among nations. This occurs due to variations in resource availability, labor costs, and production efficiencies. For example, countries rich in natural resources can export raw materials at lower prices, while others may specialize in high-tech goods. This comparative advantage drives international trade, allowing nations to benefit from each other's strengths. Historically, trade has been a key factor in economic development, with the Silk Road and the Age of Exploration exemplifying how price differentials fostered global commerce.