Some very important persons such as Japanese Emperor Hirohito and China's Premier ZhouEnlai were kept alive during their last days by many transfusions of blood. Without knowingfurther details of their ailments, which of the following functions most likely provided the mostsignificant contribution to keeping them alive?Select one:

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 fibrinogene. provision of immune antibodies