Which statement about carbon oxides is true?

Which statement about carbon oxides is true?

• A. CO2 is a greenhouse gas and CO is poisonous and interferes with the blood's oxygen transport
• B. CO is poisonous and CO2 is a greenhouse gas
• C. Both gases are harmless
• D. They are never produced by combustion

Answer: (A)

Carbon oxides have very different impacts: carbon dioxide acts as a greenhouse gas that traps heat in the atmosphere, while carbon monoxide is a toxic gas that interferes with oxygen delivery in the body. Carbon dioxide’s ability to absorb infrared radiation means more heat stays in the lower atmosphere, contributing to climate warming. Carbon monoxide is dangerous because it binds strongly to hemoglobin, forming carboxyhemoglobin, which reduces the blood’s capacity to carry oxygen to tissues. So the statement is true because you’re recognizing both roles: CO2 as a greenhouse gas and CO as a poisonous gas that disrupts oxygen transport. Statements that claim both gases are harmless or that they are never produced by combustion don’t fit, since combustion readily produces CO2 and, under incomplete combustion, CO as well.

Carbon oxides have very different impacts: carbon dioxide acts as a greenhouse gas that traps heat in the atmosphere, while carbon monoxide is a toxic gas that interferes with oxygen delivery in the body. Carbon dioxide’s ability to absorb infrared radiation means more heat stays in the lower atmosphere, contributing to climate warming. Carbon monoxide is dangerous because it binds strongly to hemoglobin, forming carboxyhemoglobin, which reduces the blood’s capacity to carry oxygen to tissues.

So the statement is true because you’re recognizing both roles: CO2 as a greenhouse gas and CO as a poisonous gas that disrupts oxygen transport. Statements that claim both gases are harmless or that they are never produced by combustion don’t fit, since combustion readily produces CO2 and, under incomplete combustion, CO as well.