A nurse learns that which of the following is the single biggest risk factor for developing cancer?

Rationale: A. While exposure to carcinogenic chemicals (such as asbestos, benzene, or pesticides) increases cancer risk, it is not the most significant overall risk factor. Occupational exposure accounts for a smaller proportion of cancer cases compared to age-related cellular changes. B. Tobacco use is the leading preventable cause of cancer and is strongly linked to cancers of the lung, mouth, throat, and bladder. However, it is not the single biggest overall risk factor when considering all populations and cancer types. C. Certain viruses, such as human papillomavirus (HPV), hepatitis B and C, and Epstein–Barr virus, can contribute to cancer development, but viral infections account for a smaller percentage of total cancer cases compared to age-related risks. D. Advancing age is the single biggest risk factor for developing cancer. As individuals age, there is increased cumulative exposure to carcinogens, decline in immune surveillance, and greater likelihood of genetic mutations over time. Most cancers occur in adults aged 55 years and older, making age the most significant non-modifiable risk factor for cancer development.