This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Environment and health, Subject name: Social & Preventive Medicine
[{'content': 'True about sand flea - \nSelect and explain. \nA. Not found in India, B. Cuases ulcer in foot, C. Caused bubo, D. Causes plague', 'role': 'user'}, {'content': "Answer: A \nExplanation: Sand fleas occur in the tropical regions of Africa and America. They are also known as Jigger or Chigoe fleas (Tunga penetrans) The feilized female burrows into the skin of the feet, often beneath the nail and cause ulcers. Tetanus and gas gangrene occur as a secondary infection REFERENCE: PARK'S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICINE, 25TH EDITION, PG NO. 839", 'role': 'assistant'}]