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: Skin
A 30 year old male presented with ulcerative lesion on glans penis. Wright- Giemsa stain showed 1-2 rounded structure in macrophage vacuoles. What is the etiology 
Select and explain. 
A. Chlamydia trachomatis, B. N. gonorrhoea, C. H. ducreyi, D. Calymatobacterium granulomatis
D: Calymatobacterium granulomatis
Answer: D: Calymatobacterium granulomatis 
Explanation: D i.e. Calymatobacterium granulomatis