Final answer:
The therapeutic approach used by a CTRS in this scenario is Validation, as it involves acknowledging and accepting the client's feelings and experiences without challenging their perception of reality.
Step-by-step explanation:
A Certified Therapeutic Recreation Specialist (CTRS) allowing a client with dementia to express frustrations related to the client's perception of being ignored by staff is likely using the Validation therapeutic approach. Validation therapy is centered on the idea of accepting the reality and personal truth of another person's experience, particularly in cases of dementia where the person's experience and feelings are acknowledged without necessarily grounding them in the current reality.
This is contrary to Reality Orientation, which focuses on helping individuals stay aware of time, place, and person. Remotivation and Reminiscence therapies involve rekindling interests and recalling past memories, respectively, which are not directly related to the therapeutic goal described in the question.