一道很简单的语法题求解释!in recent years

一道很简单的语法题求解释!in recent years
in recent years travel companies have succeeded in selling us the idea ____ the further we go,the better our holiday will be.
A,of which B where C which D that
为什么选D用同位语?
选B用定语从句where＝in which表示.will be in the idea?
为什么不能说 the further we go,the better our holiday will be in the idea.用in which？