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: Orthopaedics
True regarding mallet finger is : 
Select and explain. 
A. Avulsion of tendon at the base of the middle phalanx, B. Avulsion of extensor tendon at the base of the distal phalanx, C. Fracture of distal phalanx, D. Fracture of the proximal phalanx
B: Avulsion of extensor tendon at the base of the distal phalanx
Answer: B: Avulsion of extensor tendon at the base of the distal phalanx 
Explanation: Mallet finger is avulsion of extensor tendon from distal phalanx of a finger.