Final answer:
Transitional paragraphs in essays are (D) used to aid in smooth transitions by connecting sections in a logical way and providing background information, making the writing more coherent and comprehensible.
Step-by-step explanation:
In essays, transitional paragraphs—often just a few sentences long—are used to aid in smooth transitions between sections or ideas by connecting them in a logical manner. These paragraphs can provide background information, summarize previous arguments, or preview what is to come, thereby guiding readers to understand the flow of ideas. Transitional words and phrases within paragraphs also perform a similar role, making the writing coherent and easier to follow.
For example, if a student is writing about the need for a traffic light at a street leading into their college, and the next paragraph begins with 'Moreover, the recent increase in pedestrian traffic...', this transition signals to the reader that the author is building upon a previous point with additional evidence or arguments.
Ultimately, transitional elements like paragraphs and words are essential for creating a clear and logical structure within an essay, helping readers to comprehend how the various parts of the argument are interconnected.