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
Bennett's fracture is fracture dislocation of base of metacarpal : 
Select and explain. 
A. 4th, B. 3rd, C. 2nd, D. 1st
D: 1st
Answer: D: 1st 
Explanation: Benett's fracture is an intra - articular fracture dislocation of the palmar base of first metacarpal bone of the thumb with either subluxation or dislocation of first carpometacarpal joint, i.e. trapezometacarpal joint.