This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
Diffuse esophageal dilatation on barium swallow is seen in – a) Achlasiab) Trypanosomiasisc) Etidronate therapyd) Scleroderma 
Select and explain. 
A. ac, B. ab, C. ad, D. bc
B: ab
Answer: B: ab 
Explanation: Diffuse esophageal dilatation is seen in -
i) Primary achalasia Achalasia cardia
ii) Secondary achalasia Chaga's disease (trypanosomiasis), MEN, Triple 'A' (Allgrove's) syndrome, cancer invading LES (Pseudoachalasia).