This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper limb : Miscellaneous, Subject name: Anatomy
Medial boundary of the anatomical snuffbox is formed by: 
Select and explain. 
A. Extensor pollicis brevis, B. Extensor carpi radialis longus, C. Extensor pollicis longus, D. Extensor carpi radialis brevis
C: Extensor pollicis longus
Answer: C: Extensor pollicis longus 
Explanation: Anatomical snuff box is lined posteromedially - extensor Pollicis longus Anterolaterally - extensor pollicis brevis and abductor pollicis longus. floor - scaphoid,trapezium, base of 1st metacarpal and styloid process of radius. content - radial aery (Pulse can be felt by palpating radial aery against scaphoid bone.