This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Which of the following is the organism causing chronic burrowing ulcer? 
Select and explain. 
A. Peptostreptococcus, B. Streptococcus viridans, C. Streptococcus pyogenes, D. Microaerophilic streptococci
D: Microaerophilic streptococci
Answer: D: Microaerophilic streptococci 
Explanation: Chronic Burrowing ulcer is also known as Meleney's ulcer. This type of ulcer is caused by a hemolytic microaerophilic Streptococci, and usually develops after surgery on the intestinal or genital tract. Ref: A Manual On Clinical Surgery, By, S.Das,Page, 52, 53; Oxford Textbook Of Surgery, 2000, 2nd Edition, Page 105; Textbook of Surgery By Gupta, 2nd edition page 66.