When a man inhales air containing normal concentration of `O_(2)` as well as CO he suffers from suffocation because

Options

A. CO reacts with `O_2` reducing its percentage in air
B. haemoglobin combines with CO instead of `O_2` and forms carboxyhaemoglobin
C. CO affects diaphragm and intrecostal musceles
D. CO affects the nerves of the hungs

Answer

B

Explanation

The affinity of carbon monoxide for haemoglobin is 200 times more than oxygen, At 0.5 partial pressure, CO combines with 50% of haemoglobin. It produces a relatively stable compound called carboxy-haemoglobin. This causes a low supply of oxygen to the body which is characterised by headache, dizziness, nausea, etc.