In the atmosphere is not in a form that plants can use.

1.hydrogen
2.carbon
3.nitrogen
4.none of the above

the most logical answer would be a

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.