Answer:
a. only conflicts where a U.S. ally was a participant
Explanation:
The Cold War was a political, economic, social, military, informative and scientific confrontation initiated after the end of the Second World War between the Western (Western-Capitalist) bloc led by the United States, and the Eastern bloc (Eastern-Communist) led by the sovietic Union.
The reasons for this confrontation were essentially ideological and political. On the one hand, the Soviet Union financed and supported revolutions, guerrillas and socialist governments, while the United States gave open support and propagated destabilizations and coups, especially in Latin America and Africa. In both cases, human rights were seriously violated.
Although these confrontations did not lead to a world war, the seriousness of the economic, political and ideological conflicts marked a significant part of the history of the second half of the 20th century. The two superpowers certainly wished to implant their model of government throughout the planet.
Some subsidiary wars of this era were: the Greek Civil War, the Korean War, the Vietnam War, the Cuban Revolution, the Lebanese Civil War, the Angolan Civil War, the Afghan-Soviet War, the Gulf War and Guatemala's civil war.
