<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A previously healthy 13-year-old girl is brought to the physician by her parents because of a 2-day history of low-grade fever, headache, nausea, and a sore throat. Examination of the oral cavity shows enlarged, erythematous tonsils with exudates and palatal petechiae. There is cervical lymphadenopathy. Her parents agree to her participating in a study of microbial virulence factors. A culture of the girls throat is obtained and an organism is cultivated. The physician finds that the isolated organism is able to withstand phagocytosis when placed in fresh blood. The most likely explanation for this finding is the expression of which of the following?? A: IgA protease, B: Protein A, C: Streptolysin O, D: Hyaluronidase, E: M Protein,  <response>: This is a medical question asking about the likely explanation for an organism being able to withstand phagocytosis when placed in fresh blood. The patient is a 13-year-old girl with symptoms of sore throat, fever, headache, nausea, enlarged and erythematous tonsils with exudates and petechiae, and cervical lymphadenopathy. A throat culture was obtained that grew an organism able to withstand phagocytosis in fresh blood. Based on the patients symptoms and culture results, this is likely a streptococcal infection. The question is asking about which virulence factor would explain the organisms ability to resist phagocytosis. IgA protease, protein A, and hyaluronidase are not involved in resisting phagocytosis. Streptolysin O is a pore-forming toxin that can lyse phagocytes, but is not directly involved in resisting phagocytosis. M protein is an antiphagocytic surface protein expressed by group A streptococcus that inhibits binding and ingestion by phagocytes. Therefore, M protein is the most likely explanation for the organisms ability to withstand phagocytosis.E: M Protein 