Identify the topic sentence in the paragraph: Climate change poses serious risks. Rising sea levels threaten coastal communities. Extreme weather events disrupt agriculture.

• A. Rising sea levels threaten coastal communities.
• B. Extreme weather events disrupt agriculture.
• C. Climate change is a myth.
• D. Climate change poses serious risks.

Answer: (D)

The main idea being tested is how a topic sentence introduces the overall claim the paragraph will support. In this paragraph, the sentence “Climate change poses serious risks.” serves as that broad claim. It sets the scope and purpose, then the next lines provide concrete examples—rising sea levels threatening coastal communities and extreme weather disrupting agriculture—that illustrate the kinds of risks involved. The other options describe individual consequences or present a false claim, which don’t establish the paragraph’s central point. So the sentence that states that climate change poses serious risks is the best topic sentence because it clearly introduces the idea the rest of the paragraph develops.