The following excerpt about United States foreign policy.
On April 10, 1971, nine American players, four officials, and two spouses, accompanied by 10 journalists, crossed a bridge from Hong Kong into mainland China . . . [On] April 14, the United States lifted a 20-year-old trade embargo against China . . . and that summer, in the aftermath of the goodwill established . . . President Richard M. Nixon announced that he, too, would go to China the following year. . . .
The excerpt describes which U.S. government program?
Open Door Policy
Dollar Diplomacy
Ping-Pong Diplomacy
Monroe Doctrine