What strategy should researchers use to ensure that they protect older adult participants who are cognitively impaired or who reside in settings for the chronically ill?

As for the appointment of a sorogate decision maker on behalf of the cognitive impaired adult participants.

Explanation:

A surrogate decision maker is an individual who makes decisions for incompetent adults. If an adult who is a subject in a study is unable to make decisions for themselves, a surrogate decision maker does it on his/Her behalf. This is aimed at protecting impaired adults from exploitation by researchers. In the case of a minor, the parents or legal guardian can make those decisions on his or her behalf

dont understand question can you makeit more better

i would say b. research typically uses a variety of sources