You are answering a USMLE-style medical question. Question: A researcher conducts multiple experiments to establish an infection and disease model for Clostridium perfringens in chickens. To ensure that all instruments are free of the pathogenic organism, he uses a disinfectant that oxidizes and denatures proteins. Which of the following disinfectants did the researcher most likely use? Options: A) Chlorine dioxide B) Isopropyl alcohol C) Povidone-iodine D) Benzalkonium chloride Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.