This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Imaging of Alveolar Lung Disease, Subject name: Radiology
Water lily sign on chest X ray is seen in - 
Select and explain. 
A. Tuberculosis, B. Hydatid cyst, C. Cryptococcosis, D. Aspergillosis
B: Hydatid cyst
Answer: B: Hydatid cyst 
Explanation: Ans. is 4b' i.e., Hydatid cysto Radiological signs of hydatid cyst of lungMeniscus signWater-lilly signCamalote signRising sun signSerpent signEmpty cyst sign