This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General Microbiology Pa 1 (History, Microscopy, Stains and Structure and Physiology of Bacteria), Subject name: Microbiology
[{'content': 'All organisms show bipolar staining except - \nSelect and explain. \nA. Calymatobacter granulomatis, B. Yersinia pestis, C. H. influenzae, D. Burkholderia pseudomallei', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Safety pin like appearance (Bipolar staining) (both ends densely stained and a clear central area) is seen in - Y. pestis H. ducreyi Calymatobacter granulomatis Vibrio parahemolyticus Burkhodelderia pseudomallei Burkhodelderia mallei Gram, Wright, Wayson (or methylene blue staining) or Giemsa stain is used for demonstration of the typical bipolar (safety pin) morphology.', 'role': 'assistant'}]