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
[{'content': 'Back spattering is - \nSelect and explain. \nA. The negative pressure in the barrel, sucking blood and tissues, B. Passive agent in sodomy, C. Gushing of blood from the exit gunshot wound, D. Gushing of blood due to aerial bleed', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The synopsis of forensic medicine & toxicology ; dr k.s narayan reddy ;28th edition ;pg.no. 130 Back spattering is seen in case of contact shot where there is sucking in of blood ,hair,fragments of tissues & cloth fibers several cm. Back inside the barrel .', 'role': 'assistant'}]