Although all the choices can contribute to deepen the knowledge of the students about languages, I think the most appropriate would be the computer room.

deepen 是动词 deep（深的）加上后缀 -en 构成的动词，-en 后缀表示“使变得……”，所以 deepen 的意思是“使加深、深化”。在句中，deepen 是动词原形，跟在 contribute to 后面表示“有助于加深”。