This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Mechanical injuries, Subject name: Forensic Medicine
Brown colour of contusion is due to 
Select and explain. 
A. Hematoidin, B. Reduced haemoglobin, C. Hemosiderin, D. Bilrubin
C: Hemosiderin
Answer: C: Hemosiderin 
Explanation: age of contusion Time since injury Color change First day red(hemoglobin) 2-3 days blue (deoxyHb) 4-5 days bluish black/brown(hemosiderin) 5-6 days greenish(hematoidin) 7-10days yellow(bilirubin) By 14 days normal ref: FORENSIC MEDICINE AND TOXICOLOGY Dr PC IGNATIUS THIRD EDITION PAGE 118