A 28 year old female presented with complains of difficulties in swallowing liquids only. She also suffers from recurrent chest infection in the past few months. What is the most probable diagnosis?

The key is C. Achalasia cardia. [Dysphagia to both solid and liquid or mostly to liquid is common feature of achalasia. In achalasia there may occur aspiration due to regurgitation during lying down to sleep which may result in recurrent chest infection and cough].