Which of the following describes el niño?

a. a reversal of ocean currents and water temperatures in the mid-pacific region

b. a stream of seawater that flows in the oceans, caused by global winds at the equator

c. the result of a process by which dry areas develop on the leeward sides of mountain ranges

d. an annual pattern of strong winds and severe flooding in southeast asia and australia

The correct answer is A. A reversal of  ocean currents and water temperatures in the mid-Pacific region

Explanation:

"El Niño" is a meteorological phenomenon that occurs in cycles between three and seven years in the tropical zone of the Pacific Ocean, very close to the coasts of South America. When "El Niño" occurs, it is produced by the warming of the Pacific Ocean.  

The name was given by the fishermen in northern Peru. They observed that from time to time the cold waters of the Humboldt current, which bathes the coasts of this region, warmed during Christmas, causing that the fishes started to disappear, dangerously threatening their livelihoods. This event was called "El Niño Stream", as it was related to Catholic Christmas and the birth of the child Jesus, son of Holly Mary and Saint Joseph.  

When this phenomenon occurs, storms are more intense and frequent in the western coast of the United States. There is also more intense rainfall on the west coast of South America. However, the atmosphere seeks balance. If it rains more in North and South America, it means that South Asia and Australia, which are usually rainy, will be abnormally dry and there will be droughts.