This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Aerial disorders, Subject name: Surgery
Allen's test is useful on evaluating:- 
Select and explain. 
A. Thoracic outlet compression, B. Presence of cervical rib, C. Integrity of palmar arch, D. Digital blood flow
C: Integrity of palmar arch
Answer: C: Integrity of palmar arch 
Explanation: Allen's test is useful for evaluating the integrity of palmer arch.