Marcus is a gerontologist who is studying the degree of impairment that elders face in things such as bathing, dressing, eating, and walking. he is using a common set of measures known as:

Marcus is a gerontologist who is studying the degree of impairment that elders face in things such as bathing, dressing, eating, and walking. he is using a common set of measures known as Activities of Daily Living (ADLs), they are a set of tasks or behaviors that a person performs on a daily basis and that allow them to live autonomously and integrated into their environment and fulfill their role or roles within society.

C; skin, is the answer!