Well this is a trick question.
Plot structure is exactly what it looks like, the structure of a plot, so any of these could be true, really. However I don't think its B, because there is no details about motivation in a plot. Depending on what type of story you're reading, you wouldn't exactly see different viewpoints unless it's in third person or it switches characters, which is too specific so I don't say D. I don't say C either because details and character views enhance the setting, not necessarily the plot.
So I say A, because its really the most logical.
