关于声音的传播，下列说法中正确的是（   ）

A．只有气体和液体能传播声音，固体不能传播声音

B．固、液、气体都能传播声音，且传播速度相同

C．声音在气体中传播时受到阻碍较小，传播速度较大

D．要想听到声音，必须有声源、传播声音的介质和良好的听觉器官

— Do you know whether they talked about their work or their family

— As _______matter of fact, I couldn't hear it clearly, as they talked in ______whisper.[ ]

A. the; a      

B. a; a        

C. the; the          

D. a; the