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
Blue colour of bruise is due to 
Select and explain. 
A. Hemosiderin, B. Deoxyhemoglobin, C. Bilirubin, D. Hematoidin
B: Deoxyhemoglobin
Answer: B: Deoxyhemoglobin 
Explanation: Age of contusion Time since injury Color change First day red(Hb) 2-3 days blue(deoxyHb) 4-5 days bluish black/brown(hemosiderin) 5-6 days greenish(hematoidin) 7-10 days yellow(bilirubin) By 14 days normal Ref: FORENSIC MEDICINE AND TOXICOLOGY DR PC IGNATIUS THIRD EDITION PAGE 118