The first thing which a person must do in order to determine the central idea of An Essay on Man is:
According to the given question, we are asked to state the first thing which a person must do in order to determine the central idea of An Essay on Man.
As a result of this, we can see that whenever a person wants to identify the central idea of a text, he would first have to read and identify the topic because it would give him a good idea on what the author is writing about.
Therefore, the correct answer is option D
Read more about central idea here:
https://brainly.com/question/5955771
