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: Anatomy
Grynfeltt triangle not bounded by 
Select and explain. 
A. 12th rib, B. Paraspinal muscles, C. Internal oblique muscle, D. External oblique muscle
D: External oblique muscle
Answer: D: External oblique muscle 
Explanation: Lumbar hernias- Hernias through the superior lumbar triangle (Grynfeltt triangle) are more common and bounded by the 12th rib, paraspinal muscles, and internal oblique muscle. Inferior Lumbar / Petit triangle- bounded by the iliac crest, latissimus dorsi muscle, and external oblique muscle.