the introduction of an academic paper must include a\nthesis statement.\ntransition sentence.\nquotation.\nre…

Brief Explanations:

The thesis statement is a crucial element in an academic - paper introduction as it presents the main argument or claim. A transition sentence is more for moving between paragraphs, a quotation can be used but is not a must, and a restatement is usually for the conclusion.

Answer:

thesis statement.