This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuromuscular disorders, Subject name: Orthopaedics
What is wrong for Game keeper's thumb? 
Select and explain. 
A. 1st metacarpophalangeal joint involvement, B. Tear of ulnar collateral ligament, C. Forced Ulnar detion is the cause, D. Also called skier's thumb
C: Forced Ulnar detion is the cause
Answer: C: Forced Ulnar detion is the cause 
Explanation: Game keeper's thumb: Also called skier's thumb MC injury of 1st MCP joint Ulnar collateral ligament tear due to forced radial detion