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: Microbiology
Granuloma inguinale is caused by 
Select and explain. 
A. H. ducreyi, B. Chlamydia trachomatis, C. Treponema pallidum, D. Calymmatobacterium
D: Calymmatobacterium
Answer: D: Calymmatobacterium 
Explanation: Granuloma venereum (granuloma inguinale) → caused by Calymmatobacterium granulomatosis.
Lymphogranuloma venereum (lymphogranuloma inguinale) →  Caused by chlamydia trachomatis (serotypes L1, L2, L3).