Answer:
The description that best defines the central idea of an information text is:
B. the main point the author is trying to make.
Explanation:
The central idea of a text, and that includes information texts as well, is the main point the author is trying to convey, that is, the information he wants people to understand and remember. To support that main idea, to make it understandable, or even to prove it right, the author must use examples, evidence, details, and analysis.
Therefore, options A, C, and D consist of support to the central idea, while option B defines it.