Final answer:
During a major ENSO event, water temperature can rise as much as 5°C due to the interaction between the ocean and the atmosphere. The correct answer is b.
Step-by-step explanation:
A major ENSO event refers to El Niño-Southern Oscillation, which is a climate pattern that affects the tropical Pacific region. During a major ENSO event, water temperature can rise as much as 5°C. This increase in temperature is due to the interaction between the ocean and the atmosphere, causing changes in weather patterns and ocean currents. The correct answer is b.