Final answer:
The 18-year-old with a traumatic head injury in the ICU is at the greatest risk for developing sensory deprivation.
Step-by-step explanation:
The client who is at the greatest risk for developing sensory deprivation is the 18-year-old with a traumatic head injury who is in the ICU. Sensory deprivation occurs when there is a lack of meaningful sensory stimuli, and this client's condition and environment in the ICU may restrict their ability to receive sensory input. The head injury may affect their ability to see, hear, smell, taste, and touch, further exacerbating the risk of sensory deprivation.
On the other hand, the 84-year-old with progressive hearing loss living in an assisted living facility (option a) may have limited hearing, but they would still be able to receive other sensory stimuli. The 50-year-old with breast cancer (option b) and the 32-year-old with a fractured pelvis on bed rest in a private room (option c) may have some limitations in mobility and physical activity, but they would still have access to sensory input.