Final answer:
Tobacco smoke contains chemicals like nicotine, tar, and carbon monoxide that can cause lung cancer.
Step-by-step explanation:
Tobacco smoke contains dozens of chemical substances that are known to cause cancer, including nicotine, tar, and carbon monoxide. These chemicals can bind to DNA in a smoker's cells, causing mutations that can lead to the development of lung cancer. Therefore, the correct answer is 4) All of the above.