The correct answer is **C. at-risk**.
A non-verbal adult is someone who does not speak or use verbal communication. This can be due to a variety of factors, such as autism, Down syndrome, or a physical or developmental disability. Non-verbal adults are at an increased risk of social isolation, communication difficulties, and educational and employment challenges.
The other options are not as accurate descriptions of Celso. **Diverse** refers to a group of people with different backgrounds, experiences, and perspectives. **Impoverished** refers to someone who is living in poverty. **Rehabilitated** refers to someone who has been restored to a condition of good health, mind, or spirit.
Here are some other terms that could be used to describe Celso:
* Communication-impaired
* Autistic
* Down syndrome
* Developmentally disabled
It is important to use language that is accurate and respectful when describing people with disabilities.