You should always be descriptive enough about the source you are citing to provide context for the results. You can usually do this in one sentence. In Option 2 above, I used two sentences (the second and third sentences), but usually you can do it in one. Then, be very precise with your language about who believes what or which finding explained what. Be as concise as you can with your language, but don’t cut out important content that will allow the reader to understand what material belongs to which source, and what material moves back to your own discussion.