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
Pneumocystis carinii is a fungus because -a) rRNA, mitochondrial protein gene sequence & presence of thymidylate synthaseb) Cell wall contains glucansc) Antifungals are effective against P. cariniid) Commonest infection in AIDS 
Select and explain. 
A. abc, B. bc, C. acd, D. bcd
A: abc
Answer: A: abc 
Explanation: None