If by the statement you mean the main idea, or the argument, presented by the author, which the essay argues for this would be 1) thesis. Thesis is a statement that someone proposes and tries to defend and prove.
A critical essay is a type of academical paper in which the purpose of the author is to analyze, examine and evaluate critically some material such as a novel, story, article, etc. Similar to other essays the ideas in critical essays are developed according to one main statement or claim the author proposes in the introduction and proves using arguments and evidence during the body paragraphs. This main claim or statement is called thesis or thesis statement and shows the author's position towards the subject, which in the case of a critical essay is the author's interpretation of the material being analyzed. Considering this, it can be concluded the statement in a critical essay that shows the writer's or author's interpretation is the thesis.
