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
The mechanism of injury of transverse fracture of medial malleolus results due to -a) Abduction injuryb) Adduction injuryc) Rotation injuryd) Direct injury 
Select and explain. 
A. a, B. bc, C. ad, D. ac
D: ac
Answer: D: ac 
Explanation: Transverse fracture of medial malleolus occurs in Pronation-abduction and pronation-external rotation injury.