Hello. Unfortunately, you did not enter the text to which this question refers, nor did you provide any answer options. This makes it impossible for your question to be answered. However, I will try to help you in the best possible way.
To answer this question it is necessary that you read the entire text to which it refers, because only then will you know how to identify the central idea of the text. This central idea refers to the subject to which the text focuses on discussing and presenting. Generally, the central idea is presented right at the beginning of the text, as it already situates the reader on what will be presented, but this does not always happen. An easy way to discover the central idea is to read the entire text and then ask yourself "What was this text about?" Your answer to this question will be the central idea of the text.