It seems that I have seen this man somewhere before, but now I can’t remember    I came across him.

A．where was it that

B．where it was that

C．that it was where

D．that was it where

患儿，女，2岁半，因"发热3天伴咳嗽"入院。与当地医院按肺炎抗感染治疗，不见好转，于是转我院治疗。胸片显示，双肺纹理增多。

该患儿最大可能诊断是()

A.毛细支气管炎

B.败血症

C.支气管肺炎

D.小儿肺结核病

E.病毒感染

F.支原体感染