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: Surgery
A patients complains of occasional vomiting of food paicles eaten a few days ago. His wife repos that his breath smells foul. The most likely diagnosis is ? 
Select and explain. 
A. Pyloric obstruction, B. Carcinoma stomach, C. Carcinoma esophagus, D. Achalasia cardia
D: Achalasia cardia
Answer: D: Achalasia cardia 
Explanation: Ans. is 'd' i.e., Achalasia cardia