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 40 year old male presents with a painless cystic liver enlargement of four years duration without fever or jaundice. The most likely diagnosis is - 
Select and explain. 
A. Amoebic liver abscess, B. Hepatoma, C. Hydatid cyst of liver, D. Choledochal cyst
C: Hydatid cyst of liver
Answer: C: Hydatid cyst of liver 
Explanation: None