<span>It's D. Someone in the apartment building is moving out. </span>
The main idea of this paragraph is that the rocks cannot be explained by science, that there is a mystery to them. This sentence contributes to that idea because it gives a specific example of one of the odd things about the rocks. Because they are on a flat surface they should not roll or move on their own, but the fact that they have a trail behind them shows that they have somehow moved. This supporting statement is then supported by more details about the trails.
<span>Logical connections are important for coherence</span>
Do u want us to make a random sentence?
