This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdominal wall ,Inguinal and Femoral region, Subject name: Anatomy
Flexors of lumbar spine are all EXCEPT: 
Select and explain. 
A. Erector spinae, B. External oblique muscle, C. Internal oblique muscle, D. Rectus abdominis
A: Erector spinae
Answer: A: Erector spinae 
Explanation: Forward flexors: Rectus abdominis, external abdominal oblique, internal abdominal obliques, transversus abdominis and iliacus-psoas. Lateral flexors: Ipsilateral contraction of the oblique and transversus abdominal muscles and quadratus lumborum.