The answer is c, that's right. Let's start with item B. APEC is an economic cooperation organization and a regional multilateral organization. It opens every year, but it only opens in Shanghai at 0 1. This topic emphasizes the bilateral relations between China and the United States. Item A, the establishment of diplomatic relations between China and the United States is 1979. 1, which has little to do with Shanghai after Deng Xiaoping's visit to the United States. Item C, Nixon's visit to China 1972, on February 28th, on behalf of the United States and China respectively, the two countries issued the Shanghai Communiqué (this is one of the three joint communiqué s, and the other two are the Communiqué on the Establishment of Diplomatic Relations and the August 17th Communiqué). The two countries ended their opposition and began to contact. D, China's reform and opening up is an internal affair, not international relations!