This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Microbiology
which is responsible for the above condition 
Select and explain. 
A. sporothrix schenki, B. mycobacterium marinum, C. recketssia akari, D. mycobacterium ulcerans
B: mycobacterium marinum
Answer: B: mycobacterium marinum 
Explanation: Fish Tank Granuloma * Caused by atypical mycobacterial infection * Recreational or occupational exposure to contaminated freshwater or saltwater * Affects elbows, knees, feet, knuckles or fingers * Often single lump which causes crusty sore or abscess * Other lumps on course of lymphatic drainage * More widespread if immuno-compromised * Treated with long course of minocycline or co-trimoxazole 6-12 weeks ref : ananthanaryana 9th ed