At Rest, the _______ PO₂ in Blood at the Lungs

Multiple Choice

At rest, the _______ PO₂ in blood at the lungs allows hemoglobin to carry _______ O₂ molecules, but when the blood returns to the lungs, hemoglobin usually carries _______ O₂ molecules.

A) high; four; no
B) low; four; no
C) high; four; three
D) low; two; no
E) high; three; four