The population of this city, forty percent of which ________, __

The population of this city, forty percent of which ________, ________ 15% in the last three years.
A、are Germans; has risen by
B、are German; has fallen by
C、is Germans; have increased to
D、is Germans; has been reduced try
【正确答案】：A
【题目解析】：考查population的用法以及主谓一致。句意：这个城市的人口40%是德国人，在过去的三年中已经增加了15%。population强调人口是多少时，若作主语，谓语动词用单数形式。population强调人口的身份或特征，若后面作表语的名词是复数时，谓语动词则要用复数形式。