Final answer:
To confirm her diagnosis, Dara should contact the CDC, which is the main national public health institution responsible for disease tracking and confirmation.
Step-by-step explanation:
If Dara wants to get confirmation that her diagnosis is correct, she would most likely reach out to CDC (Centers for Disease Control and Prevention). The CDC is a federal agency that conducts and supports health promotion, prevention, and preparedness activities in the United States with the goal of improving overall public health. While OSHA (Occupational Safety and Health Administration) focuses on workplace health and safety, the FDA (Food and Drug Administration) on food and drug safety, and NIOSH (National Institute for Occupational Safety and Health) on workplace safety research, the CDC is the primary national public health institution that would handle disease confirmation and provide information on various health conditions.