1). A topic is the subject, while the central idea is what the writer thinks about the topic after research.
Explanation:
The key difference between a topic and a central idea is that topic is characterized as the subject of the essay while central idea is described as the primary idea that author would focus upon which he thinks after conducting his research on the topic. Topic is broader term and refers to a category of general area of interest and the central idea functions to explain the subject the author is going to deal with and displays his stand on it. Thus, the main idea is a part of the topic and includes it and hence, <u>option 1</u> is the correct answer.
