Answer:
Option B. Adding a topic sentence to a paragraph is an example of revising.
Step-by-step explanation:
When writing an essay or text, revising it is a key step within the process. Revising comes after writing the first draft of the text, and it means to focus on the ideas and organization of the text. When revising, the author should pay attention to the general outcome of each paragraph, in order to arrange the information, whether by adding missing sentences or concepts, or by removing non-necessary information. This is why, in the process of revising the author can add a topic sentence to a paragraph, to give this last one a better structure and make it more comprehensible for the reader.