This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Parasitology, Subject name: Microbiology
ARC-5 in countercurrent electrophoresis of serum is diagnostic of: 
Select and explain. 
A. Cysticercosis, B. Cryptococcosis, C. Hydatidosis, D. Brucellosis
C: Hydatidosis
Answer: C: Hydatidosis 
Explanation: Ans. is 'c' i.e., Hydatidosis(Ref: Harrison, 19th/e, p. 1433)* Serological test for hydatid cyst: Precipitin reaction, Complement fixation test, Hemagglutination test, Flocculation test, IFA, Immuno electrophoresis (Arc 5) test.Detection of antibody to specific echinococcal antigens by immunoblotting has the highest degree of specificity. Q