What organ serves as the control center for the regulation of erythropoiesis?

The kidneys produce erythropoietin, that regulates erythropoiesis.

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

Ithink the answer is d.