[单选题]Read the following paragraph and choose the best topic sentence from the four options that follow.Writing a summary is an excellent way to understand what is read. This in itself is an important goal of academic study. If you don't understand your source material, chances are that you will not be able to refer to it usefully in an essay or a research paper. Summaries help you understand what you read because they force you to put the text into your own words. Practice of writing summaries also develops your overall writing skills,since a good summary,like any other piece of good writing, is clear, coherent, and concise. Summaries are useful to your readers as well.You can best demonstrate the source material to your readers by summarizing it if they are not familiar with it. Summaries are required frequently in academic writings. In critique papers, you summarize material in order to critique it;in synthesis papers, you summarize to show relationships between sources. A Summary writing serves various purposes in academic study. B The purpose of a summary is to facilitate academic reading. C A good summary should demonstrate clarity and coherence. D A summary is a shorter version of the source material.