The liberal approach can perhaps be best summarized by the writings of Adam Smith who argues that the key to national wealth, and therefore national power, is economic growth. The key to economic growth is free trade, the free flow of goods, services and investment across borders. Hence, political leaders should allow trade among nations to expand and keep government intervention in that trade down to a minimum. This means that imports and exports should flourish with as little restriction as possible. The correct answer is A.