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">