Which of the following was primarily instrumental in decreasing the historical tension between People's Republic of China (PRC) and the Republic of China (ROC)?
A. ROC acquiring U.N membership.
B. Rise of communism.
C. Increase in direct trade.
D. American military involvement in peacekeeping.
E. ASEAN mandates overruling former hostilities between member nations.
Answer: C. Increase in direct trade.