I think it is answer B. Sorry if it's wrong.
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.
Answer:
To see the dingy could come drooping down,obscuring everything,one might have thought that natural live hard by,and was brewing on a large scale.
Explanation: