The correct answer is Raising the tariffs.
Harding administration passed the Emergency Tariff Act in the year 1921. Raised tariffs was mainly on farm products. By raising tariffs on foreign goods, foreign products become more expensive. As a result of the increased prices on foreign goods, the U.S citizens would purchase items manufactured within their own country, in return raising their countries economy.
The Emergency Tariff of 1921, increased rates on wheat, sugar, meat, wool and other agricultural products brought into the United States from foreign nations. Hence, protecting the domestic producers of those items.