This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdominal Radiography, Subject name: Radiology
Sign (Arrows) on Abdominal radiograph indicate 
Select and explain. 
A. Crohn's disease, B. Ulcerative colitis, C. Small bowel obstruction, D. Ileocaecal Tuberculosis
C: Small bowel obstruction
Answer: C: Small bowel obstruction 
Explanation: Small bowel obstruction {Sign: String of bead sign)