Final answer:
William H. Taft's foreign policy approach that encouraged companies to build railroads, post offices, and government buildings in countries they wanted to do business with was known as "dollar diplomacy."
Step-by-step explanation:
William H. Taft's foreign policy approach that encouraged companies to build railroads, post offices, and government buildings in countries they wanted to do business with was known as "dollar diplomacy." Taft sought to secure markets and opportunities for American businessmen by using economic power instead of military force. His goal was to use foreign policy to benefit the United States economically.