Final answer:
The first step in the prewriting stage is Choosing your topic, which is fundamental before you can narrow it down, gather details, or consider your audience and purpose.
Step-by-step explanation:
The first step in the prewriting stage of writing is C. Choosing your topic. Before you can narrow down your topic, gather details, or consider your audience and purpose, you need to have a general idea of what you will be writing about. Choosing a topic that interests you is crucial because it helps maintain enthusiasm throughout the writing process and contributes to a more engaging presentation for your audience.
Once a topic is chosen, the next steps, such as brainstorming to narrow down your topic, gathering details for your content, and considering your audience and the purpose of your writing, can follow. This organized approach allows you to create a focused and effective piece of writing that communicates your ideas clearly and persuasively to your intended audience.