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
A child presented with a fall on an outstretched hand with the elbow in full extension. On examination there is pain and swelling over his right elbow. The probable diagnosis is: 
Select and explain. 
A. Fracture olecranon, B. Post dislocation of elbow, C. Supracondylar fracture of humerus, D. Fracture both bones forearm
C: Supracondylar fracture of humerus
Answer: C: Supracondylar fracture of humerus 
Explanation: Supracondylar fractures are the most common fracture about the elbow in children. They can be either extension type (>95%), which are displaced posteriorly, or flexion type (Extension type injuries most often occur with a fall on an outstretched hand with the elbow in full extension. The patient will have significant edema and tenderness at the elbow, a prominent olecranon, and a depression proximal to the elbow. The appearance may be easily mistaken for a posterior elbow dislocation. Ref: Bredenkamp J.H., Jokhy B.P., Uehara D.T. (2011). Chapter 267. Injuries to the Elbow and Forearm. In J.E. Tintinalli, J.S. Stapczynski, D.M. Cline, O.J. Ma, R.K. Cydulka, G.D. Meckler (Eds), Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 7e.