Which action characterized Earth's earliest atmosphere (atmosphere I) ? A.) Heat energy was retained and water vapor condensed.

B.) Helium and hydrogen gases escaped earth's gravity.

C.) Ultraviolet light split water vapor into hydrogen and oxygen.

D.) Increased oxygen allowed reptiles to thrive.

answer; ///i believe its: ///(embolus);

the truman doctrine was an american foreign policy whose stated purpose was to counter soviet geopolitical expansion during the cold war. it was announced to congress by president harry s. truman on march 12, 1947, and further developed on july 12, 1948, when he pledged to contain threats to greece and turkey.