Answer:
A. a descriptive example of parkitecture
Explanation:
In order to further develop the idea of the text, adding a descriptive example of parkitecture will be best to achieve that.
The idea of the passage is to inform the reader about parkitecture. It tells the reader the time this style of design flourished. It also tells the reader how the design style looks like.
But in order to buttress on the idea, adding a descriptive example of parkitecture will develop the idea more and create a visual picture of how parkitecture looked in the twentieth century.
Option A is the correct answer.
