This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Small & Large Intestine, Subject name: Surgery
In Meckel's diverticulum, ectopic gastric tissue is diagnosed by: 
Select and explain. 
A. Radionucleotide scan, B. Endoscopy, C. Ultrasound, D. RBC tagged scanning
A: Radionucleotide scan
Answer: A: Radionucleotide scan 
Explanation: Ans: a