Answer is D.
Desert and tundra regions are marked by their absence of trees, which indicates little to no rainfall in the area.
The topic—"Literary devices in American poetry"—would be a weak topic because such a topic is extremely vague and not specific enough.
American poetry uses many, MANY literary devices—and many of which are not unique to American poetry alone. Also, "American poetry" in general is too broad of topic.
Answer:
Environmental distractions.
