The correct answer is:
a concise summary of the central idea of a text.
Explanation: A thesis statement serves as the central argument or claim of an essay or research paper. It clearly presents the main idea that the author intends to support or explain throughout the text. A well-crafted thesis statement is not just a statement of fact but an assertion that can be backed up with evidence and analysis. Therefore, it is characterized by its conciseness and focus on the central idea, distinguishing it from general information, introductory paragraphs, or detailed summaries of key points.