The main idea of an essay or argument is called what?

• A. Key idea
• B. Controlling idea
• C. Thesis
• D. Structure

Answer: (C)

The main idea being tested is the thesis: the clear, specific claim that states what the essay is arguing or proving. The thesis sets the purpose and direction for the whole piece, so every paragraph and piece of evidence ties back to it. A strong thesis is debatable and concise, guiding the reader to what will be supported with reasons and evidence. For example, in a persuasive essay about uniforms, the thesis might say that requiring uniforms improves discipline and academic focus, and the rest of the essay would provide reasons and data to back that up. While a key idea can be an important point in the text, it’s not necessarily the central claim of the whole argument; structure refers to how the essay is organized, not to the claim itself.