Which of the following is a fungus -: (A) Klebsiella, (B) Clostridia, (C) Pneumocystis jerovecii, (D) Listeria
Answer is C. Pneumocystis jerovecii is considered to be fungus based on following points:

It takes fungal stains like Gomori’s methanamine silver stain
It possesses chitin at all stages of development (component of fungal cell wall)
Based on molecular study of 5S –rRNA.