What is one way the author uses a cause-and-effect structure to support his purpose?

The purpose of the cause-and-effect essay is to determine how various phenomena relate in terms of origins and results. Sometimes the connection between cause and effect is clear, but often determining the exact relationship between the two is very difficult. For example, the following effects of a cold may be easily identifiable: a sore throat, runny nose, and a cough. But determining the cause of the sickness can be far more difficult. A number of causes are possible, and to complicate matters, these possible causes could have combined to cause the sickness. That is, more than one cause may be responsible for any given effect.

Explanation:

In the literary field, the essay text is defined as Cause and Effect Essay, which aims to reflect, expose and demonstrate the different relationships that may exist between a fact identified as a cause and its consequences, so that both situations also become the basis of the thesis or hypothesis that the author proposes from the beginning.  

The experts advise to choose for the extension and writing of the Essays of Cause and Effect the traditional structure of five paragraphs, in which the author will be exposing the different phases or arguments of his position, in order to demonstrate his thesis when presenting a causal or diagnostic situation, where the author can take a particular phenomenon, either social or scientific, in order to search in its own nature the causes that provoke it, in order not only to conclude that it is these situations that cause it, thus verifying its initial thesis, but also to have the possibility of proposing a solution, in case it is a negative phenomenon, or even to propose some type of improvement, in case it is a positive element, but that can always be perfected.

i think that the best option for this question is

d)to persuade readers that a prince must eradicate the royal family of a conquered principality.

i hope this .

the correct answer is:   [c]:

                    →     " leave it out. "  

hope this is to you!

        best wishes!