PT 59 S3 Q3

Hemoglobin, a substance in human blood, transportsoxygen from the lungs ... ...

Which one of the following is most strongly supported by the information above?
(A) A hemoglobin molecule that has picked up three oxygen molecules will probably acquire a fourth oxygen molecule.
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Complete Section: LR-B, Dec. '09 LSAT (PT 59 Sec. 3)