Supporting evidence should be presented in

a. the introduction, right after the thesis statement.

b. the body, right after subtopic statements.

c. the conclusion, to give weight to closing arguments.

d. all sections of the essay, so that the thesis is supported throughout.

The correct answer is B. The body, right after subtopic statements.

It's not everywhere because you should not provide new supporting evidence in the conclusion. Conclusions should restate and paraphrase what was previously mentioned. The introduction is not it as well because there is usually nothing after the thesis statement as it has a tendency to be the final sentence in the introduction paragraph.