Including Keffer's memory helps achieve the author's purpose because the author's purpose is to inform, and this informs the reader about pedestrians, and what they should do! It's important to know what Keffer remembered because it helps achieve the authors' purpose, and adds on to more information mentioned earlier in the text. It also gives us Keffer's point of view!
D. An astronaut can't resist the temptation to push a mysterious red
button on her control panel.