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: Pediatrics
2 year old boy presented with abdominal distension, chronic diarrhoea, severe anaemia and failure to thrive. Which of the following is the investigation of choice? 
Select and explain. 
A. Intestinal biopsy, B. Antinuclear antibody, C. Antiendomyseal antibody, D. Anti milk protein antibody
C: Antiendomyseal antibody
Answer: C: Antiendomyseal antibody 
Explanation: The given clinical feature suggest diagnosis of Celiac disease. Anti endomyseal antibody and anti tissue transglutaminase antibody help in diagnosis of celiac disease.