Each red blood cell carries about 250 million molecules of hemoglobin. how many molecules of oxygen could a single red blood cell deliver throughout the body if every hemoglobin molecule attached to four oxygen molecules? a. 1 trillion molecules of oxygen b. 1 x 10 to the power of 8 molecules of oxygen c. 1 billion molecules of oxygen d. 1 x 10 to the power of 10 molecules of oxygen