This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: GIT and hepatobiliary system, Subject name: Radiology
Barium swallow is used for - 
Select and explain. 
A. Colon, B. Esophagus, C. Duodenum, D. Jejunum
B: Esophagus
Answer: B: Esophagus 
Explanation: Barium swallow is the contrast study from oral cavity upto the fundus of stomach. Indications : Dysphagia and obstruction Motility disorders of esophagus. Assessment of site of esophageal perforation Zenker's diveiculum and cricoid webs. Contraindications : Tracheo esophageal fistula Esophageal perforation