Final answer:
Nurses should use the various theories on aging to guide nursing care, encompassing biological, social, and psychological aspects of aging, rather than adhering to a single theory.
Step-by-step explanation:
Several theories on aging are employed in the field of geriatrics to inform nurses and healthcare providers about the most effective ways to care for the elderly. Rather than adhering to a single theory, nurses should use these theories to guide nursing care. Aging theories encompass a range of perspectives including biological changes (e.g., free radical theory), social concerns (e.g., modernization theory), and psychological aspects (e.g., Kubler-Ross's five stages of grief), which facilitate a comprehensive approach to geriatric care. The appropriate response to the student's question would be Option A: Guide nursing care. The various aging theories provide insights into the complexities of aging, which can influence how nurses address both the physiological and psychosocial needs of elderly patients.