Final answer:
The construction of private bomb shelters was the American public's direct reaction to Cold War tensions, reflecting widespread fears of nuclear conflict.
Step-by-step explanation:
The reaction by the American public to the tensions created by the Cold War can be seen in various ways, but the most apparent response reflecting those tensions was C. The construction of private bomb shelters. During this era, fears of nuclear conflict were prevalent, which led to American families taking measures to protect themselves, such as building private bomb shelters in their homes. This domestic phenomenon was part of a broader culture of preparedness and was fueled by government campaigns encouraging citizens to prepare for the possibility of a nuclear attack.
The Cold War era also saw a host of other reactions, including loyalty oaths, investigations to root out perceived communist sympathies, and a rise of anticommunist sentiment in foreign and domestic policies. Despite economic prosperity and consumerism in areas such as popular culture, for many Americans, the Cold War era was marked by a sense of anxiety about the potential for communist subversion and nuclear war.