When reading an informational text, how do you identify the author's thesis statement?

A- The thesis statement is the first sentence of the introduction, in which the author introduces the topic for the first time.
B- The thesis statement is found at the end of the conclusion and summarizes the supporting details in the text.
C- The thesis statement is the sentence found at the beginning of each body paragraph and is followed by supporting details.
D- The thesis statement is the sentence in the introduction that states the author's specific ideas about the topic.