Which poisonous gas is commonly produced by automobile exhaust systems?

• A. Nitrogen dioxide (NO_2)
• B. Carbon monoxide (CO)
• C. Methane (CH_4)
• D. Sulfur dioxide (SO_2)

Answer: (B)

Verified step by step guidance

1. Understand that the question asks about a poisonous gas commonly produced by automobile exhaust systems.
2. Recall that automobile engines burn fuel in the presence of oxygen, but often the combustion is incomplete, leading to the formation of certain gases.
3. Identify that carbon monoxide (CO) is a colorless, odorless, and poisonous gas produced by incomplete combustion of carbon-containing fuels, such as gasoline in cars.
4. Recognize that nitrogen dioxide (NO_2) and sulfur dioxide (SO_2) are pollutants but are more commonly associated with industrial emissions and burning of fossil fuels containing nitrogen and sulfur, respectively.
5. Note that methane (CH_4) is a greenhouse gas but is not typically a major component of automobile exhaust.