Some very important persons such as Japanese Emperor Hirohito and China's Premier Zhou Enlai were kept alive during their last days by many transfusions of blood. Without knowing further details of their ailments, which of the following functions most likely provided the most significant contribution to keeping them alive? (A) oxygen and carbon dioxide carrying capacity
(B) supplement of hormone levels
(C) provision of organic nutrients such as glucose, amino acids, and fats
(D) provision of albumin and fibrinogen
(E) provision of immune antibodies