The example that reflects a way Adam Smith thought the government should be involved in the economy is:
The government builds a road from a city to a major seaport and charges a fee for cars to drive on that road.
Adam Smith believed that the government should provide certain public goods and infrastructure, such as roads, which are necessary for commerce and trade, but should generally allow markets to operate freely. Building and maintaining infrastructure is a role Smith would support, as it facilitates economic activity.