I bought two hats yesterday in the store, ________ will go with my red coat．
A.the redder oneB.the redder of whichC.redder of whichD.the reddest of which在线课程B
考查比较级。这里是指两顶帽子之间较红的那个，应使用the redder of…，再根据句子结构可知，这又是一个非限制性定语从句，因此整个答案为the redder of which。