What happens during an El Niño-Southern Oscillation (ENSO) ? 

A)  surface water along the South and North American coasts becomes cooler 
B)  prevailing easterly winds weaken 
C)  upwelling's of warm, nutrient-poor water are suppressed 
D)  upwelling's of cold, nutrient-rich water are suppressed

El Niño-Southern Oscillation

A climate phenomenon characterized by the periodic warming of sea surface temperatures in the central and eastern Pacific Ocean, affecting weather patterns globally.

Prevailing Easterly Winds

Winds that typically blow from the east, common in tropical regions close to the equator due to the Earth's rotation and atmospheric conditions.

Upwellings

The rising of deep, cold, and nutrient-rich water to the surface, fostering significant biological productivity.