A community health nurse is preparing an educational activity on Alzheimer's disease. Which of the following risk factors should the nurse include as the greatest risk for this disease?

A. Androgen deprivation therapy has been linked in some studies to cognitive changes, but it is not a primary or major risk factor for Alzheimer’s disease in the general population. Its impact is limited and less significant compared with age-related risk. B. History of Down syndrome increases the risk of early-onset Alzheimer’s due to the extra copy of chromosome 21, which carries the amyloid precursor protein gene. While this is a significant risk in this population, it affects a relatively small subset of individuals and is not the leading risk factor for the general population. C. Genetics (e.g., APOE-e4 allele) increases susceptibility, particularly for late-onset Alzheimer’s, but genetics alone does not account for the majority of cases. Environmental and lifestyle factors interact with genetic risk. D. Age is the greatest risk factor for Alzheimer’s disease. The prevalence rises sharply with advancing age: individuals 65 years and older are at significantly higher risk, and the likelihood increases further after age 85. Aging-related changes in the brain, including amyloid accumulation and neurofibrillary tangle formation, are central contributors to the disease process.