There are three key features that should be included in an introduction: Background information, Thesis statement, Purpose and structure of essay. Please select from the following descriptions the incorrect one.
选项：

A:Background information helps to frame the composition as an argumentative essay.;
B:The purpose and structure of the essay are specified either in the middle or at the end of the introduction.;
C:Thesis statement allows them to become “tuned in” to the problem under discussion.;
D:---