TT GWD-8-13没有找到讨论的解释

Q13:

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)

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

我也想问：请问这里what指代什么? 多谢！