Final answer:
A scientist would likely use a model to answer a question about the formation of a lake, as modeling is suitable for understanding complex or long-term processes such as geological formations.
Step-by-step explanation:
A scientist would be most likely to use a model to answer the question: How was this lake formed? This is because modeling can help to simulate geological processes and the historical formation of natural features. For questions about the current temperature of a lake or the composition of a rock at the bottom of the lake, direct measurements rather than modeling would be more appropriate and accurate.
Models are invaluable in science for understanding complex systems and predicting future states based on current understanding. They are particularly useful for answering questions about processes that occur over long periods of time or are too large, too small, or too complex to replicate in real life. Thus, a model could be used to understand lake formation which involves geological and environmental processes over long time scales.