This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2018, Subject name: Microbiology
[{'content': 'Quellung reaction is seen with: \nSelect and explain. \nA. Pneumococcus, B. Gonococcus, C. Streptococcus, D. Staphylococcus', 'role': 'user'}, {'content': "Answer: A \nExplanation: Quellung reaction Capsular swelling due to serological reaction Pneumococcal Capsular antigen + Antibody causes Capsular swelling Note:- MC fadyean's reaction Done for bacillus anthracis capsule (polypeptide)", 'role': 'assistant'}]