Read the following passage: "While often used interchangeably, 'weather' and 'climate' describe distinct phenomena. Weather refers to the atmospheric conditions at a specific place and time, encompassing short-term variations in temperature, precipitation, humidity, wind, and cloud cover. It can change rapidly, from sunny skies to a thunderstorm within hours. Climate, conversely, represents the average weather patterns over a longer period, typically 30 years or more, for a particular region. It includes statistics like average temperature and rainfall, as well as the frequency of extreme events. Understanding this distinction is crucial for discussing global warming, which refers to a long-term change in climate, not just a temporary shift in weather." A scientist observes unusually cold temperatures and heavy snowfall in a region during a single winter season. Based on the passage, how should this observation be primarily categorized?

1. AAs a typical example of regional climate.
2. BAs evidence of a long-term climate change trend.
3. CAs a short-term variation in weather.
4. DAs an indicator of global warming.