A 12-year-old girl has a history of recurrent bulky stools and abdominal pain since 3 years of age. She has moderate pallor and her weight and height are below the 3rd percentile. Which of the following is the most appropriate investigation to make a specific diagnosis?: (A) Small intestinal biopsy, (B) Barium studies, (C) 24-hr- fecal fat estimation, (D) Urinary d-xylose test
Answer is A. None