75.嚴重複合性免疫缺陷小鼠(SCID)的肺臟未見塌陷(如下左圖),其H&E染色切片下發現特殊病變如下右圖,最可能的致病原為下列何者? (A)adenovirus (B)Filobacterium rodentium(舊稱cilia-associated respiratory bacillus) (C)Mycoplasma pulmonis (D)Pneumocystis murina