Which cigarette-smoke component is described as reducing oxygen transport in the blood?

### Why this is right Carbon monoxide is the component identified in the material as reducing the blood's ability to transport oxygen. This can contribute to reduced oxygen availability in the body. ### The concept Cigarette smoke contains thousands of chemicals, and the material highlights three examples with different effects. Nicotine is addictive and affects the nervous system. Tar contributes to lung-tissue damage and cancer. Carbon monoxide interferes with oxygen transport in the blood. These effects are distinct, even though the substances occur within the same smoke exposure. ### The other options - **A. Nicotine**: This is identified as addictive and as affecting the nervous system, not as the named cause of reduced oxygen transport. - **B. Tar**: This contributes to lung-tissue damage and cancer; it is not the component assigned the oxygen-transport effect. - **D. Mucus**: This is produced in the airways and can obstruct airflow when excessive; it is not a cigarette-smoke chemical named in the question's context. ### Terms - **Carbon monoxide**: A harmful gas in tobacco smoke that reduces the blood's oxygen-transport capacity. - **Tar**: A mixture of smoke substances associated in the material with lung-tissue damage and cancer. - **Nicotine**: An addictive substance in tobacco smoke that affects the nervous system. ### Remember Link nicotine with addiction, tar with tissue damage, and carbon monoxide with reduced oxygen transport.