This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Orthopaedics
Which of the following site is least commonly involved in ahrogryposis ? 
Select and explain. 
A. Knee, B. Hip, C. Trunk, D. Elbow
C: Trunk
Answer: C: Trunk 
Explanation: . ref : maheswari 9thed essentials of pediatric ohopedics 5th ed