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: Surgery
Jersey finger is caused by rupture of: 
Select and explain. 
A. Flexor digitorum superficialis, B. Flexor digitorum profundus, C. Extensor digiti minirni, D. Extensor indicis proprius
B: Flexor digitorum profundus
Answer: B: Flexor digitorum profundus 
Explanation: Ans: B. Flexor digitorum profundus(Ref Bailey 26/e p465)Rugger jersey finger:Caused by rupture of flexor digitorum profundus.Injury to flexor profundus tendon at its attachment point to distal phalanx.Occurs mostly in American football when a player grabs another player's jersey with the tips of one or more fingers while that player is pulling or running away."