William Howard Taft, during his presidency from 1909 to 1913, aimed to implement a foreign policy known as "Dollar Diplomacy," which sought to promote American commercial interests abroad while maintaining stability in those regions, including China.
Among the options provided, the best answer is:
He tried to extend the Open Door policy deeper into Manchuria.
Taft believed in promoting U.S. trade in Asia and wanted to ensure that American businesses had access to Chinese markets, particularly in the Manchuria region, which was of strategic interest to various powers, including Japan. His approach aimed to strengthen the Open Door Policy, rather than replace or cancel it.