It is only a ____ of time before the rebels surrender.

It is only a ____ of time before the rebels surrender.
A、problem
B、means
C、thing
D、matter
【正确答案】：A
【题目解析】：problem 问题；means 方法；thing 事；matter 事件；句意：叛军投降只是时间的问题。因此A 正确