Answer: Topic sentences have a dual purpose to communicate the purpose of the paragraph and relate the paragraph back to the thesis. Or if you talking about something exciting, topic sentences have a dual purpose to communicate the purpose of the paragraph and provide exciting details.
Explanation: Hope this helps:)
The sentence that best represents the function of a supporting sentence is, option B. It adds more details to the topic sentence. The supporting sentences make up the paragraph that talks about the main sentence. The supporting sentences not only add more information about the topic, but also add examples to further explain the main sentence.