Question: In sentence (3), Katrina's instructor underlined the phrase, "naturally occurring arsenic has leaked into the town's water, making it unsafe" and written expand this idea next to it in the margin. What could Katrina do to improve this idea in her paragraph? She could bring in information that explains how towns fight pollution in their water supplies. She could provide additional information that shows why and how the leak of arsenic into the town's water supply makes it unsafe for residents. She could cut this sentence out of her paragraph.