How should a reader analyze a text to identify its theme?

Responses
1) by examining the author's purpose for writing the text
2) by looking for an idea that interacts with all the elements
3) by summarizing the plot development
4) by identifying the elements

that the author uses to support the theme

WHICH ONE IS THE RIGHT ANSWER?

The correct answer is option 2) by looking for an idea that interacts with all the elements.