This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Anatomy
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: Clinical features of hydatid disease Equally common in males and females, age 45 years Most(75%) are singular, located in right liver Mostly asymptomatic until complications occur Most common presenting symptoms - abdominal pain, dyspepsia and vomiting Most common sign- Hepatomegaly Ref:Sabiston 20th edition Pgno :1452