This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pseudomonas, Subject name: Microbiology
[{'content': 'Which of the following is responsible for green color on antibiotic disk sensitivity testing? \nSelect and explain. \nA. Pyoverdin and pyocyanin, B. Pneumolysin, C. Optochin, D. Alpha hemolysin', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Pyoverdin and pyocyanin.* Pseudomonas produce pigments by the name of pyoverdin and pyocyanin leading to greenish pigmentation in culture plate.* Pneumococci produce pneumolysin that break downs hemoglobin into a green pigment. This causes pneumococcal colonies to be surrounded by green zone during growth on blood agar plates. The plate in question is not blood agar.Image source- style="font-family: Times New Roman, Times, serif">', 'role': 'assistant'}]