Final answer:
The correct order for performing the examinations is 2, 1, 3: IVU, UGI, Barium Enema.
Step-by-step explanation:
The correct order for performing the examinations is c. 2, 1, 3.
The IVU (Intravenous Urogram) should be performed first as it involves injecting a contrast dye into the vein and then taking X-ray images to visualize the urinary tract.
The UGI (Upper Gastrointestinal) examination should be performed second, as it involves swallowing barium sulfate and then taking X-ray images to visualize the esophagus, stomach, and small intestine.
The Barium Enema should be performed last, as it involves filling the colon with barium sulfate and then taking X-ray images to visualize the large intestine.