This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
Which of this part of vertebral canal will show secondary curves with concavity backwards? 
Select and explain. 
A. Cervical, B. Thoracic, C. Sacral, D. Coccyx
A: Cervical
Answer: A: Cervical 
Explanation: Primary curvatures (concavity forwards) → thoracic and sacral.
Secondary curvatures (concavity backwards) → cervical and lumbar.