What does the scientist believe has an effect on the weather?

The correct answer is that the scientist believes it was natural. This indicates that the scientist attributes the influence on weather to natural processes or phenomena, rather than to human activities or historical events. In the context of meteorology and climate science, natural factors can include elements such as atmospheric conditions, ocean currents, and solar radiation, all of which play significant roles in shaping weather patterns.

Choosing this answer reflects an understanding that many weather events are driven by inherent environmental processes that have been occurring over long time scales, rather than being influenced heavily by human action or other factors. For example, natural climate patterns like El Niño or seasonal changes are important considerations in weather forecasting and analysis.

The other options suggest different influences on weather. While "man-made" could pertain to human impact on climate, such as through pollution or urbanization, it contradicts the notion of attributing weather effects purely to natural processes. "Historical" might imply that past events or conditions have shaped current weather, but it lacks the immediacy of natural phenomena. "Predictable" refers to the ability to forecast weather based on patterns rather than the causal factors themselves, which further highlights that the correct choice emphasizes a belief in natural causation.