Excessive release of the pollutant carbon monoxide (CO) into the air may produce a condition in which oxygen supply in the human body decreases. What causes this condition ?

• A. When inhaled into the human body, CO is converted into CO2
• B. The inhaled CO has much higher affinity for hemoglobin as com­pared to oxygen
• C. The inhaled CO destroys the chemical structure of haemoglobin
• D. The inhaled CO adversely affects the respiratory centre in the brain