Based on the options, the most logical is D:)
You ask yourself, "what is the main idea?" "what is the story about?". The theme is like the things that the story surrounds.
Answer: If you repeat an experiment multiple times, you get better, thorough, answers.
Explanation: Rather than Billy doing it once, he should have done it multiple times to get the results he needed. Especially with science, there are a lot of mistakes and things we can’t control: It is very important that we try over and over again. The wind, the time, the angle, anything can affect and ruin data. But, if we continue to gather it and be precise as possible, the results won’t always be 100% inaccurate and can at least be estimated upon.
