A 25-year-old woman is brought to the emergency department after being found unconscious near the doorway of a smoke
-filled house. Temperature is 37.3°C (99.1°F), pulse
is 120/minute, respirations are 20/min, and blood pressure
is 110/65 mm Hg. Physical examination shows generalized flushing of the skin as well as black soot near the nares and mouth. There is no evidence of any burns
or trauma. Capillary refill time is 5 seconds. Supplemental oxygen is administered. Laboratory results are shown below. Hydroxocobalamin is provided for medical management. Which of the following best describes the mechanism of action of this medication?