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
Which organism cannot be cultured -a) Klebsiella rhinoscleromatisb) Klebsiella ozaenaec) Klebsiella granulomatisd) Pneumocystis jirovecie) Rhinosporidium seeberi 
Select and explain. 
A. de, B. bc, C. cd, D. bd
A: de
Answer: A: de 
Explanation: "The life cycle of pneumocystis probably involves sexual and asexual reproduction, although definitive proof awaits the development of a reliable culture system".
─ Harrison
"Rhinosporidium seeberi has not been cultivated in media". 
─ Ananthnarayan.