Final answer:
El Niño is linked to the extra snow in the Rocky Mountains in 1997.
Step-by-step explanation:
The correct answer is A. El Niño. El Niño is a climate pattern that occurs when the waters of the eastern Pacific Ocean are warmer than average. This warming can have a significant impact on weather patterns around the world. In the case of the Rocky Mountains experiencing record snowfalls in 1997, the warmer-than-average water temperatures in the eastern Pacific Ocean likely triggered an El Niño event, leading to extra snowfall in the region.
Learn more about El Niño and snowfall in the Rocky Mountains