Name a major risk factor for bladder cancer.

• A. Alcohol consumption
• B. Regular exercise
• C. High-fiber diet
• D. Smoking

Answer: (D)

Smoking is the major risk factor for bladder cancer because carcinogens from tobacco are absorbed into the bloodstream, filtered by the kidneys, and concentrated in the urine. As urine sits in the bladder, these chemicals repeatedly contact the urothelium, causing DNA damage that can lead to malignant transformation of bladder cells. The risk increases with how much and how long a person has smoked, and it declines after quitting, though it takes years to approach baseline levels.

Other options do not have the same strong, well-established link to bladder cancer. Alcohol use isn’t a major driver of bladder cancer, and while regular exercise and a high-fiber diet are generally healthy, they do not pose a high risk for bladder cancer in the way tobacco exposure does.