An author's ____ is his or her reason for writing a text.

• A. idea
• B. belief
• C. purpose
• D. assumption

Answer: (C)

The main idea here is that the reason an author writes a text is called the purpose. The purpose is the motive behind the work, guiding what the author tries to achieve, such as informing, persuading, or entertaining. That’s why purpose is the best fit for the prompt: it directly states why the text exists and what the author intends to accomplish, which shapes the tone, evidence, and structure.

An idea is the topic or concept the text covers, not the motive for writing. A belief is a held conviction that can influence how the author presents material, but it isn’t the stated reason for writing. An assumption is a premise the argument builds on, not the purpose of the text.