A leading figure in the Scottish enlightenment, Adam Smith’s two major books are to democratic capitalism what Marx’s Das Kapital is to socialism.

1. Adam Smith’s two major books are to democratic capitalism what

2. Adam Smith’s two major books are to democratic capitalism like

3. Adam Smith’s two major books are to democratic capitalism just as

4. Adam Smith wrote two major books that are to democratic capitalism similar to

   E. Adam Smith wrote two major books that are to democratic capitalism what
  

ANSWER：E 

选E时，句子成分是怎么样的呢？我选的C为什么错啊?不是很平行么?

The correct answer is C, while answer E is obviously ungrammatical with the use of WHAT.

agree to C