This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Embryology and abdominal wall layer, Subject name: Anatomy
Smallest abdominal muscle is: 
Select and explain. 
A. External oblique, B. Internal oblique, C. Transversalis, D. Rectus abdominis
C: Transversalis
Answer: C: Transversalis 
Explanation: The transverse abdominis is the smallest of the four abdominial muscles and lies deep to the others.