The correct answer to this open question is the following.
Although there are no options attached we can say the following.
An example of the government restricting business in order to promote the welfare of U.S. Citizens is a government regulation to impede foreign companies to compete in the United States so US companies can sell their products and services.
Taxation, more specifically, import taxes or trade barriers, have been government regulations that the United States federal government has used in the past throughout US history in order to protect American companies.
However, these decisions have not been the best ones. Foreign companies took the exact same measures against US products in retaliation.