Final answer:
The aging population in the U.S. includes a substantial proportion of baby boomers who are now retiring, increasing demand for healthcare and extending the average lifespan (option A).
Step-by-step explanation:
As the aging population in the United States increases, the nurse should be aware that the baby boomer generation comprises a significant portion of this group. These individuals, born between 1946 and 1964, number approximately 74 million and are now reaching retirement age. This surge in the elderly population leads to a greater need for healthcare due to common age-related health issues such as heart conditions, arthritis, and Alzheimer's. Consequently, there will be an increased demand for hospitalization, long-term, and at-home nursing care.
Furthermore, the extension of the average life span has also increased due to advances in medical technologies and life-saving treatments. Lastly, with the implementation of initiatives like the Affordable Care Act, access to healthcare services has expanded, although future developments could influence this trend.
Hence, the answer is option A.