To determine which statement about carbon monoxide (CO) is incorrect, let's analyze each option:$\\$• Option 1: $$It reduces oxygen carrying ability of blood.$\\$Carbon monoxide binds with hemoglobin to form carboxyhemoglobin, which reduces the blood's ability to carry oxygen.$\\$This statement is correct.$\\$• Option 2: $$The carboxyhaemoglobin (haemoglobin bound to CO) is less stable than oxyhaemoglobin.$\\$Carboxyhemoglobin is actually more stable than oxyhemoglobin. The bond between CO and hemoglobin is much stronger than that of oxygen,$\\$making it difficult for oxygen to displace CO. This statement is incorrect.$\\$• Option 3: $$It is produced due to incomplete combustion.$\\$Carbon monoxide is indeed produced when carbon-containing fuels are burned incompletely.$\\$This statement is correct.$\\$• Option 4: $$It forms carboxyhaemoglobin.$\\$As mentioned earlier, CO binds with hemoglobin to form carboxyhemoglobin.$\\$This statement is correct.$\\$Therefore, the incorrect statement is Option 2, which states that carboxyhaemoglobin is less stable than oxyhaemoglobin.$\\$Thus, the correct answer is Option 2.