关于慢性支气管炎的发病因素，以下哪一项是错误的

A．呼吸道局部防御功能和免疫功能低下

B．自主神经功能失调

C．呼吸道黏液分泌功能减退

D．呼吸道黏液分泌功能亢进

There is a real possibility that these animals could be frightened, ________ a sudden loud noise. [      ]

A. being there    

B. there being    

C. should there be    

D. there was