Transitions should be used in various parts of writing to ensure clarity and coherence. Therefore, the answer includes:
A. Between paragraphs - Transitions help to connect the ideas of different paragraphs smoothly. B. In your thesis statement - A clear thesis can lead into the main argument, and transitional wording can help set the stage for your essay. C. Within your paragraphs - Transitions help to connect sentences and ideas within paragraphs for better flow. D. At the end of a conclusion - Transitions can help relate the conclusion back to the main points or summarize important information.
Overall, transitions are useful in all these contexts. However, if you need to choose the most common use, A. Between paragraphs and C. Within your paragraphs are particularly critical for connecting ideas.