Final answer:
The symptoms described are consistent with the late stage of Alzheimer's disease, where severe cognitive and motor impairments are present.
Step-by-step explanation:
The stage of Alzheimer's disease where the individual has the inability to talk or move, experiences swallowing difficulties, cannot walk, and has rigid muscles, is generally referred to as the late stage of Alzheimer's. This progressive and terminal stage of Alzheimer's signifies severe brain damage and the individual becomes completely dependent on others for care. The symptoms you've described are consistent with the severe neurodegenerative changes of late-stage Alzheimer's disease, including cognitive and motor impairment that greatly diminish the person's quality of life and ability to interact with their environment.