单选题 No one could come up with an easy solution to the government' s predicament—labor ______. which is caused by the wars.

【正确答案】 D
【答案解析】shortage短缺。句意：战争导致劳动力匮乏，没有人能就政府的这一困境提出一个简单易行的方案。A．decline衰退；B．vacancy空白，空虚，空缺；C．rarity稀有，杰出，珍贵。