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
Not a muscle of Ist layer of foot 
Select and explain. 
A. Flexor digitorum brevis, B. Abductor Hallucis, C. Abductor digiti minimi, D. Flexor digitorum accessorius
D: Flexor digitorum accessorius
Answer: D: Flexor digitorum accessorius 
Explanation: Flexor digitorum accessorius is a muscle of 2nd layer of foot