when summarizing the of a plot, one should notice the key ideas about how the conflict builds. beginning…

Brief Explanations:

In a plot structure, the middle (also known as the rising action) is where the conflict develops and builds toward the climax. The beginning introduces the conflict, the ending/resolution resolves it, but the middle focuses on conflict building. So the correct option is the one related to the part where conflict builds, which is "middle".

Answer:

middle