The correct answer is B. CO.
Carbon monoxide (CO) is a colorless, odorless, and tasteless gas that is produced when gasoline is burned in an engine. It is a major cause of accidental poisoning and death. CO binds to hemoglobin in the blood more readily than oxygen, preventing oxygen from being delivered to the body’s tissues. This can lead to a variety of symptoms, including headache, dizziness, nausea, and vomiting. In severe cases, CO poisoning can lead to unconsciousness and death.
CO is a particular danger in enclosed spaces, such as garages, because it can build up to high levels without being detected. If you are going to leave your car running in a garage, make sure that the garage is well-ventilated and that you are not in the garage when the engine is running.
The other options are incorrect because:
- A. CO2 is carbon dioxide, which is a greenhouse gas that is not poisonous.
- C. Unburnt petrol is gasoline that has not been completely burned. It is a flammable liquid that can be a fire hazard.
- D. SO2 is sulfur dioxide, which is a gas that is produced when fossil fuels are burned. It is a major cause of acid rain.