Gender imbalance has become a serious problem in China the Chinese government is giving

问题补充：

Gender imbalance has become a serious problem in China, the Chinese government is giving serious thought to.

A. the one

B. that

C. one

D. those

答案：

A. the one

B. that

(答案→)C. one

D. those

解析：句意：在中国性别比例失调已经成为一个非常严重的问题，对于这个问题中国政府正给予特别关注。这里one 是problem的同位语，不表特指，所以前面不用定冠词。One后是一个省略了关系词that或which的定语从句，关系词在从句中做主语，故选C。