A modern city has been set up in ( ) was a wasteland ten yeas ago.A what B which C that D where 为什么?

A modern city has been set up in ( ) was a wasteland ten yeas ago.
A what B which C that D where
为什么?

答案应该是A.因为where是副词,所以首先排除,虽然that可以指city但in that不讲,而which可指几个中的某个,而根据句子的意思是说"该城市",所以答案应该是A,意思是:一座新兴城市是在十年前的废墟上建立起来的