This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteria, Subject name: Microbiology
An organism grown on agar shows green colored colonies; likely organism is: 
Select and explain. 
A. Staphylococcus, B. E. coli, C. Pseudomonas, D. Peptostreptococcus
C: Pseudomonas
Answer: C: Pseudomonas 
Explanation: Ans. is 'c' i.e., Pseudomonas(Ref: Ananthanarayan,9th/e, p. 314,319; Harrison, 19th/e, p. 1042, 1070)Pigments (Diffusible) - Pyocyanin - Bluish-green, Pyoverdin - Yellowish-green (Fluoroescin), Pyorubrin - Bright red, Pyomelanin - Brown-black.